Question

Find the LCM of the pair of polynomials. 2x^2-18 and 5x^3+30x^2+45x

a)(x+3)^2(x-3)
b)(x-3)^2(x+3)
c)10x(x+3)(x-3)
d)10x(x+3)^2(x-3)

Answer 1

d

Explanation:

Answer 2

2x^2-18 = 2( x^2 -9) = 2( x-3) ( x+3)

5x^3+30x^2+45x = 5x(x^2 + 6x+9) = 5x ( x+3) ( x+3)

LCM: Multiply each factor the greatest number of times it occurs in any of the numbers.

LCM : 2 (x-3) (x+3) * 5x (x+3)

10x (x-3) (x+3)^2

Choice D