hi, I need help with these questions:
factor
9(y-1)^2-25
16x^2+76x+90
3x^2-27(2-x)^2
-p^2q^2+81
please help. i tried to do it but I did not get it. and if you can kindly also explain the steps. i would appreciate it. Thanks.
9(y-1)^2 - 25
= (3(y-1))^2 - 5^2
= (3(y-1)+5)(3(y-1)-5)
= (3y+2)(3y-8)
16x^2 + 76x + 90
= 2(8x^2 + 39x + 45)
factors will be
(x+?)(8x+?) or (2x+?)(4x+?)
a little trial and error reveals
2(2x+5)(4x+9)
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(6-2x)(4x-6)
= 12(3-x)(2x-3)
-p^2q^2+81
= 9^2 - (pq)^2
= (9+pq)(9-pq)