To solve these equations, punnet squares are pretty helpful to use.
1 is in the picture
I'll skip around and answer a few of these.
3. 25x²-36y²=5x-6y (i just square rooted everything...)
5.x²+11x-12=(x+12)(x-1) (because -1&12 have a sum of -11 and a product of -12)
7.x^8-9x^4=(x^4+3x²)(x^4-3x²)
it looks like this: x^8-3x^6+3x^6-9x^4 and the +3x^6 and -3x^6 cancel each other out and leave us with x^8-9x^4
9.x^6-3x^3-18=(x^3-6)(x^3+3) (because -6 and 3 have a sum of -3 and a product of -18)