We read your photo as:

Here are the solutions to the mathematics problems: SECTION A (35 MARKS) 1. (6 Marks) a) Simplify: rac34 imes 3-232 b) Express 0.00032 in standard form. c) Rationalize and simplify: rac5sqrt(3)

Mathematics

ScanSolve AI Answer

Step-by-step solution

41 steps

Here are the solutions to the mathematics problems:

SECTION A (35 MARKS)

1. (6 Marks)

  • a) Simplify: 34×3−232\frac{3^4 \times 3^{-2}}{3^2}
  1. Apply the exponent rule am×an=am+na^m \times a^n = a^{m+n} to the numerator.

    $$
    3^4 \times 3^{-2} = 3^{4 + (-2)} = 3^{4-2} = 3^2
    $$
    
  2. Substitute this back into the expression.

    $$
    \frac{3^2}{3^2}
    $$
    
  3. Apply the exponent rule aman=am−n\frac{a^m}{a^n} = a^{m-n}.

    $$
    3^{2-2} = 3^0
    $$
    
  4. Any non-zero number raised to the power of 0 is 1.

    $$
    3^0 = 1
    $$
    The simplified expression is $\boxed{1}$.
    
    • b) Express 0.00032 in standard form.
  5. Move the decimal point to the right until there is one non-zero digit to its left.

    $$
    0.00032 \to 3.2
    $$
    
  6. Count how many places the decimal point was moved.

    It was moved 4 places to the right.

  7. Since the decimal was moved to the right, the exponent of 10 will be negative.

    $$
    3.2 \times 10^{-4}
    $$
    In standard form, it is $\boxed{3.2 \times 10^{-4}}$.
    
    • c) Rationalize and simplify: 53\frac{5}{\sqrt{3}}
  8. To rationalize the denominator, multiply both the numerator and the denominator by 3\sqrt{3}.

    $$
    \frac{5}{\sqrt{3}} \times \frac{\sqrt{3}}{\sqrt{3}}
    $$
    
  9. Multiply the numerators and the denominators.

    $$
    \frac{5\sqrt{3}}{(\sqrt{3})^2}
    $$
    
  10. Simplify the denominator.

    $$
    \frac{5\sqrt{3}}{3}
    $$
    The rationalized and simplified expression is $\boxed{\frac{5\sqrt{3}}{3}}$.
    
    • d) Evaluate: 50+38\sqrt{50} + 3\sqrt{8}
  11. Simplify 50\sqrt{50} by finding the largest perfect square factor.

    $$
    \sqrt{50} = \sqrt{25 \times 2} = \sqrt{25} \times \sqrt{2} = 5\sqrt{2}
    $$
    
  12. Simplify 8\sqrt{8} by finding the largest perfect square factor.

    $$
    \sqrt{8} = \sqrt{4 \times 2} = \sqrt{4} \times \sqrt{2} = 2\sqrt{2}
    $$
    
  13. Substitute the simplified radicals back into the expression.

    $$
    5\sqrt{2} + 3(2\sqrt{2})
    $$
    
  14. Multiply the terms.

    $$
    5\sqrt{2} + 6\sqrt{2}
    $$
    
  15. Combine the like terms.

    $$
    (5+6)\sqrt{2} = 11\sqrt{2}
    $$
    The evaluated expression is $\boxed{11\sqrt{2}}$.
    

    2. (7 Marks)

    • a) Expand and simplify: (2x−3)(x+5)−(x−4)2(2x-3)(x+5)-(x-4)^2
  16. Expand the first product (2x−3)(x+5)(2x-3)(x+5) using FOIL.

    $$
    (2x)(x) + (2x)(5) + (-3)(x) + (-3)(5)
    $$
    $$
    2x^2 + 10x - 3x - 15
    $$
    $$
    2x^2 + 7x - 15
    $$
    
  17. Expand the second term (x−4)2(x-4)^2 using the formula (a−b)2=a2−2ab+b2(a-b)^2 = a^2 - 2ab + b^2.

    $$
    (x)^2 - 2(x)(4) + (4)^2
    $$
    $$
    x^2 - 8x + 16
    $$
    
  18. Substitute the expanded terms back into the original expression.

    Remember to distribute the negative sign to all terms in the second expansion. (2x2+7x−15)−(x2−8x+16) (2x^2 + 7x - 15) - (x^2 - 8x + 16) 2x2+7x−15−x2+8x−16 2x^2 + 7x - 15 - x^2 + 8x - 16

  19. Combine like terms.

    $$
    (2x^2 - x^2) + (7x + 8x) + (-15 - 16)
    $$
    $$
    x^2 + 15x - 31
    $$
    The expanded and simplified expression is $\boxed{x^2 + 15x - 31}$.
    
    • b) Factorize completely: 3x2−11x−43x^2 - 11x - 4
  20. Find two numbers that multiply to 3×−4=−123 \times -4 = -12 and add up to −11-11.

    These numbers are −12-12 and 1.

  21. Rewrite the middle term using these two numbers.

    $$
    3x^2 - 12x + x - 4
    $$
    
  22. Factor by grouping.

    $$
    3x(x - 4) + 1(x - 4)
    $$
    
  23. Factor out the common binomial factor (x−4)(x-4).

    $$
    (x-4)(3x+1)
    $$
    The completely factorized expression is $\boxed{(x-4)(3x+1)}$.
    
    • c) Solve: 4x2−9=04x^2 - 9 = 0
  24. Add 9 to both sides of the equation.

    $$
    4x^2 = 9
    $$
    
  25. Divide both sides by 4.

    $$
    x^2 = \frac{9}{4}
    $$
    
  26. Take the square root of both sides, remembering both positive and negative roots.

    $$
    x = \pm\sqrt{\frac{9}{4}}
    $$
    $$
    x = \pm\frac{\sqrt{9}}{\sqrt{4}}
    $$
    $$
    x = \pm\frac{3}{2}
    $$
    The solutions are $\boxed{x = \frac{3}{2} \text{ or } x = -\frac{3}{2}}$.
    

    3. (6 Marks)

    • Solve: 3x+2y=17(Equation 1)3x + 2y = 17 \quad \text{(Equation 1)} 2x−y=4(Equation 2)2x - y = 4 \quad \text{(Equation 2)}
  27. Use the elimination method.

    Multiply Equation 2 by 2 to make the coefficients of yy opposites. 2×(2x−y=4) 2 \times (2x - y = 4) 4x−2y=8(Equation 3) 4x - 2y = 8 \quad \text{(Equation 3)}

  28. Add Equation 1 and Equation 3.

    $$
    (3x + 2y) + (4x - 2y) = 17 + 8
    $$
    $$
    7x = 25
    $$
    
  29. Solve for xx.

    $$
    x = \frac{25}{7}
    $$
    
  30. Substitute the value of xx into Equation 2 to solve for yy.

    $$
    2\left(\frac{25}{7}\right) - y = 4
    $$
    $$
    \frac{50}{7} - y = 4
    $$
    
  31. Isolate yy.

    $$
    -y = 4 - \frac{50}{7}
    $$
    $$
    -y = \frac{28}{7} - \frac{50}{7}
    $$
    $$
    -y = -\frac{22}{7}
    $$
    $$
    y = \frac{22}{7}
    $$
    The solution is $\boxed{x = \frac{25}{7}, y = \frac{22}{7}}$.
    

    4. (8 Marks)

    A projectile is modeled by h=−2t2+12t+5h = -2t^2 + 12t + 5.

    • a) Find the maximum height. The maximum height occurs at the vertex of the parabola. For a quadratic equation at2+bt+cat^2 + bt + c, the t-coordinate of the vertex is given by t=−b2at = \frac{-b}{2a}.
  32. Identify aa and bb from the equation h=−2t2+12t+5h = -2t^2 + 12t + 5.

    $$
    a = -2, \quad b = 12
    $$
    
  33. Calculate the time tt at which the maximum height occurs.

    $$
    t = \frac{-12}{2(-2)} = \frac{-12}{-4} = 3
    $$
    
  34. Substitute t=3t=3 into the height equation to find the maximum height hh.

    $$
    h = -2(3)^2 + 12(3) + 5
    $$
    $$
    h = -2(9) + 36 + 5
    $$
    $$
    h = -18 + 36 + 5
    $$
    $$
    h = 18 + 5
    $$
    $$
    h = 23
    $$
    The maximum height is $\boxed{23 \text{ units}}$.
    
    • b) Determine the time when the projectile hits the ground. The projectile hits the ground when its height hh is 0.
  35. Set the equation to 0.

    $$
    -2t^2 + 12t + 5 = 0
    $$
    
  36. Use the quadratic formula t=−b±b2−4ac2at = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}.

    Here a=−2a=-2, b=12b=12, c=5c=5. t=−12±122−4(−2)(5)2(−2) t = \frac{-12 \pm \sqrt{12^2 - 4(-2)(5)}}{2(-2)} t=−12±144+40−4 t = \frac{-12 \pm \sqrt{144 + 40}}{-4} t=−12±184−4 t = \frac{-12 \pm \sqrt{184}}{-4}

  37. Calculate the square root of 184.

    184≈13.56\sqrt{184} \approx 13.56. t=−12±13.56−4 t = \frac{-12 \pm 13.56}{-4}

  38. Calculate the two possible values for tt.

    $$
    t_1 = \frac{-12 + 13.56}{-4} = \frac{1.56}{-4} = -0.39
    $$
    $$
    t_2 = \frac{-12 - 13.56}{-4} = \frac{-25.56}{-4} = 6.39
    $$
    Since time cannot be negative, we take the positive value.  
    The projectile hits the ground at approximately $\boxed{6.39 \text{ units of time}}$.
    
    • c) Find the average rate of change between t=1t=1 and t=3t=3. The average rate of change is given by h(t2)−h(t1)t2−t1\frac{h(t_2) - h(t_1)}{t_2 - t_1}.
  39. Calculate h(1)h(1).

    $$
    h(1) = -2(1)^2 + 12(1) + 5
    $$
    $$
    h(1) = -2 + 12 + 5 = 15
    $$
    
  40. Calculate h(3)h(3).

    $$
    h(3) = -2(3)^2 + 12(3) + 5
    $$
    $$
    h(3) = -2(9) + 36 + 5
    $$
    $$
    h(3) = -18 + 36 + 5 = 23
    $$
    
  41. Calculate the average rate of change.

    $$
    \text{Average rate of change} = \frac{h(3) - h(1)}{3 - 1}
    $$
    $$
    = \frac{23 - 15}{2}
    $$
    $$
    = \frac{8}{2}
    $$
    $$
    = 4
    $$
    The average rate of change between $t=1$ and $t=3$ is $\boxed{4 \text{ units of height per unit of time}}$.
    
Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp