Question

Factorise:

(a) 9y^2 + 30y + 25 – 49b^2​

Answer 1

Step-by-step explanation:

9y² = (3y)²

30y = 2*3y*5

25=5²

49b²=7²×b²=(7b)²

9y²+30y+25 is in the form a²+2ab+b²=(a+b)², a=3y,b=5

=(3y+5)²

9y²+30y+25-(7b)²

= (3y+5)²-(7b)²

=(3y+7b+5)(3y-7b+5)

a²-b²=(a+b)(a-b)