4. 9(y-1)^2 - 25 = [3(y-1)]^2 - 5^2
= [3(y-1)+5]*[3(y-1)-5]
= (3y-2)(3y-8)
5. 3x^2 - 27(2-x)^2
= 3[x^2 - 9(2-x)^2]
= 3[x^2 - [3(2-x)]^2]
= 3[(x+3(2-x)][x-3(2-x)]
= 3(x + 6 - 3x)(x - 6 + 3x)
= 3(-2x+6)(4x-6)
= 12(3-x)(2x-3)
It's late -- someone else do 1-3
Factor
1. 8a^2-2ab-21b^2
2. 6m^2-90m+324
3.5x(2-x)+4x(2x-5)-(3x-4)
4. 9(y-1)^2-25
5. 3x^2-27(2-x)^2
1 answer