(y-3)^2=4y-12
(y-3)²=4y-12
First we need to start by subtract 4y-12 from both sides
y²-6y+9-(4y-12)= 4y-12-(4y-12)
y²-10y+21=0
Now we need to do the factorization of the equation
we gonna factor the left side of it
(y-3)(y-7)=0
Set factors equal to 0
y-3=0 or y-7=0
y=3 or y=7
I hope that's help :0