Question

(p+q)square -20 (p+q)-125 -------- factorise

Answer 1

Let p+q=x
x²–20x–125=0
x²–25x+5x–125=0
x(x–25)+5(x–25)=0
(x–25)(x+5)=0
x–25 = 0 or x+5=0
x = 25 or x = –5