Question

Which expression is equivalent to x2+3x+2

A) (x+3)(x+1)
B) (x+2)(x+1)
C) (x+2)(x-1)
D) (x+3)(x-1)

Answer 1

(a + b)(c + d) = ac + ad + bc + bd

A) (x + 3)(x + 1) = x² + x + 3x + 4 = x² + 4x + 4

B) (x + 2)(x + 1) = x² + x + 2x + 2 = x² + 3x + 2

C) (x + 2)(x - 1) = x² - x + 2x - 2 = x² + x - 2

D) (x + 3)(x - 1) = x² - x + 3x - 3 = x² + 2x - 3

Answer: B.

Answer 2

B

Explanation:

x² + 3x + 2

Sum = 3

Product = 2

Factors = 2 , 1 {2 +1 = 3 & 2*1 = 2}

x² + 2x +x + 2 = x(x + 2 ) + 1(x +2)

= (x +2)(x + 1)