Question

Can anybody tell me the answer to third question and explain it also

Answer 1

its easy.
x(x+y)+8(x+y)
=(x+y)(x+8)

part 2:
take out 5y common from the terms 15xy and 5y.also take out -2 common from the remaining terms.
5y(3x+1)-2(3x+1)
(3x+1)(5x-2)

im in college first year .Trying to help high school people here.(i said this because someone asked in comment section but now the qn is vanished)