Question

Factorise the following.
a) 4(x + 2)^2 - 9(x - 1)^2
b) 25(x - 2)^2 - 16(x + 3)^2

Answer 1

a) first expand: (2(x+2) - 3(x-1)) x (2(x+2) + 3(x-1))
then distribute: (2x+4-3x+3) x (2x+4+3x-3)
add same terms together and subtract numbers: (-x+7) x (5x-1)
final answer: (-x+7) x (5x+1)

b) same steps as before
I. (5(x-2) - 4(x+3)) x (5(x-2) + 4(x+3))
II. (5x-10-4x-12) x (5x-10+4x+12)
final answer: (x-22) x (9x+2)