Question

Solve the equation for y (y-3)^2=4y-12

Answer 1

(y -3)^2 = 4y - 12

Expand.

(y-3)(y -3) = 4y - 12

y² - 6y + 9 = 4y - 12

y² - 6y -4y + 9 + 12 = 0

y² - 10y + 21 = 0

Factors are -7y and - 3y

y² - 10y + 21 = 0

y² - 3y - 7y + 21 = 0

y(y - 3) -7(y - 3) = 0

(y - 3)(y - 7) = 0

y-3 = 0   or    y - 7 = 0

y = 0 + 3  or  y = 0 + 7

y = 3 or 7