QUESTION 1
| Expression | Number of terms | Constant term | Coefficient of x | Degree of the expression | Value of expression if x=−2 and y=−2 |
| :-------------------------- | :-------------- | :------------ | :----------------- | :----------------------- | :------------------------------------------- |
| 3x2+5+6x−7y | 4 | 5 | 6 | 2 | 19 |
| 56xy+82y2−13x−15 | 4 | -15 | -13 | 2 | 563 |
| 8x4+x2−7 | 3 | -7 | 0 | 4 | 125 |
Calculations for Question 1:
Expression 1: 3x2+5+6x−7y
- Number of terms: 3x2, 5, 6x, −7y. There are 4 terms.
- Constant term: 5.
- Coefficient of x: 6.
- Degree of the expression: The highest power is x2, so the degree is 2.
- Value if x=−2,y=−2:
3(−2)2+5+6(−2)−7(−2)
=3(4)+5−12+14
=12+5−12+14
=19
Expression 2: 56xy+82y2−13x−15
- Number of terms: 56xy, 82y2, −13x, −15. There are 4 terms.
- Constant term: −15.
- Coefficient of x: −13.
- Degree of the expression: The highest sum of powers in a term is 1+1=2 for 56xy and 2 for 82y2, so the degree is 2.
- Value if x=−2,y=−2:
56(−2)(−2)+82(−2)2−13(−2)−15
=56(4)+82(4)+26−15
=224+328+26−15
=552+26−15
=578−15
=563
Expression 3: 8x4+x2−7
- Number of terms: 8x4, x2, −7. There are 3 terms.
- Constant term: −7.
- Coefficient of x: There is no x term, so the coefficient is 0.
- Degree of the expression: The highest power is x4, so the degree is 4.
- Value if x=−2,y=−2: (Note: y is not in the expression)
8(−2)4+(−2)2−7
=8(16)+4−7
=128+4−7
=132−7
=125
QUESTION 2
2.1 State whether the following expressions are monomial, binomial, or trinomial.
2.1.1 (2x+7)×(3x2+2x−1)
Step 1: Expand the expression.
(2x+7)(3x2+2x−1)=2x(3x2+2x−1)+7(3x2+2x−1)
=6x3+4x2−2x+21x2+14x−7
Step 2: Combine like terms.
=6x3+(4x2+21x2)+(−2x+14x)−7
=6x3+25x2+12x−7
This expression has 4 terms.
The expression is a polynomial (specifically, a quadrinomial). It is not a monomial, binomial, or trinomial.
Polynomial
2.1.2 (3p+2)+(2x−1)
Step 1: Simplify the expression.
(3p+2)+(2x−1)=3p+2+2x−1
=3p+2x+1
This expression has 3 terms.
The expression is a trinomial.
Trinomial
2.1.3 8x2+2x−5x−9
Step 1: Simplify the expression by combining like terms.
8x2+2x−5x−9=8x2−3x−9
This expression has 3 terms.
The expression is a trinomial.
Trinomial
2.2 Given that a=−2, b=−3, c=2 and d=0, determine the value of the following expression:
2.2.1 (3abc)d
Step 1: Substitute the given values into the expression.
(3×(−2)×(−3)×2)0
Step 2: Calculate the value inside the parenthesis.
(3×6×2)0
(18×2)0
(36)0
Step 3: Apply the exponent rule x0=1 for any non-zero x.
=1
1
2.2.2 a−5b2+4ac
Step 1: Substitute the given values into the expression.
−2−5(−3)2+4(−2)(2)
Step 2: Perform the exponentiation.
−2−5(9)+4(−2)(2)
Step 3: Perform the multiplications.
−2−45+(−16)
−2−45−16
Step 4: Perform the subtractions.
−47−16
=−63
−63
2.2.3 36ab−31bc+2cd
Step 1: Substitute the given values into the expression.
36(−2)(−3)−31(−3)(2)+2(2)(0)
Step 2: Perform the multiplications in each term.
36(6)−31(−6)+0
216−(−186)+0
Step 3: Perform the addition.
216+186
=402
402
2.2.4 a2+2bc−31d
Step 1: Substitute the given values into the expression.
(−2)2+2(−3)(2)−31(0)
Step 2: Perform the exponentiation and multiplications.
4+2−6−0
Step 3: Perform the division.
4+(−3)−0
Step 4: Perform the subtraction.
4−3
=1
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