Solving Quadratics by Factorising

Question 1:

x27x = 0
x = 0 or x = 7

Question 2:

x2 100 = 0
x = 10 or x = -10

Question 3:

5 x2 80 = 0
x = 4 or x = -4

Question 4:

x2+3x54 = 0
x = -9 or x = 6

Question 5:

x225
x = 5 or x = -5

Question 6:

5 x2+28x12 = 0
x =25 or 6