We read your photo as:

Solve the equation: (3 x)2 - (1)/(2) 3 x = (3)/(2)

Mathematics

ScanSolve AI Answer

Answer

x=13,33x = \frac{1}{3}, 3\sqrt{3}

Step-by-step solution

4 steps
  1. Let y=log⁡3xy = \log_3 x.

    Substitute this into the given equation.
    The equation is (log⁡3x)2−12log⁡3x=32(\log_3 x)^2 - \frac{1}{2} \log_3 x = \frac{3}{2}.
    Substituting y=log⁡3xy = \log_3 x, we get:

    y2−12y=32y^2 - \frac{1}{2}y = \frac{3}{2}
  2. Rearrange the equation into a standard quadratic form ay2+by+c=0ay^2 + by + c = 0.

    Multiply the entire equation by 2 to eliminate fractions:

    2y2−y=32y^2 - y = 3

    Subtract 3 from both sides:

    2y2−y−3=02y^2 - y - 3 = 0
  3. Solve the quadratic equation for yy.

    We can factor the quadratic equation. We need two numbers that multiply to 2×(−3)=−62 \times (-3) = -6 and add up to −1-1. These numbers are −3-3 and 2.

    2y2−3y+2y−3=02y^2 - 3y + 2y - 3 = 0

    Factor by grouping:

    y(2y−3)+1(2y−3)=0y(2y - 3) + 1(2y - 3) = 0 (y+1)(2y−3)=0(y + 1)(2y - 3) = 0

    This gives two possible values for yy:

    y+1=0  ⟹  y=−1y + 1 = 0 \implies y = -1 2y−3=0  ⟹  2y=3  ⟹  y=322y - 3 = 0 \implies 2y = 3 \implies y = \frac{3}{2}
  4. Substitute back log⁡3x\log_3 x for yy and solve for xx.

    Case 1: y=−1y = -1

    log⁡3x=−1\log_3 x = -1

    By the definition of a logarithm (by=x  ⟺  log⁡bx=yb^y = x \iff \log_b x = y), we have:

    x=3−1x = 3^{-1} x=13x = \frac{1}{3}

    Case 2: y=32y = \frac{3}{2}

    log⁡3x=32\log_3 x = \frac{3}{2}

    By the definition of a logarithm, we have:

    x=33/2x = 3^{3/2} x=33x = \sqrt{3^3} x=27x = \sqrt{27} x=9×3x = \sqrt{9 \times 3} x=33x = 3\sqrt{3}

    Both solutions are valid since x>0x > 0 for log⁡3x\log_3 x.

    The solutions for xx are 13\frac{1}{3} and 333\sqrt{3}.

    x=13,33x = \frac{1}{3}, 3\sqrt{3}
Was this helpful?

Try one yourself

A new problem that tests the same skill.

Still stuck on this one?

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

Got a different question?Ask your own question