Question

Special Cases of Factoring, need the steps please.
1. y2-49
2. 4x2-25
3. 81x2 – 1
4. 16y2-8y+1

Answer 1

y^2-49= (y^2-7^2)=(y+7)(y-7)
4x^2-25=((2x)^2-5^2)=(2x+5)(2x-5)
.................

Answer 2

remember the formula:
\[a ^{2}-b ^{2}=(a-b)(a+b)\]

Answer 3

use it