Question

Factorise 9(x+y)³-16(x+y)​

Answer 1

Answer:

(x+y)[3(x+y)-4][3(x+y)+4]

Step-by-step explanation:

9(x+y)³-16(x+y)

= (x+y)[9(x+y)²-16]

= (x+y)[{3(x+y)}²-(4)²]

= (x+y)[3(x+y)-4][3(x+y)+4]

using formula x²-y² = (x+y)(x-y)