4x^2 -28x + 49=0
- move -49 to the other side
x^2-7x+49/4=0
- take out the 4 because you cannot complete the square with a coefficient in front of x^2
(x^2-7x +(7/2)^2) + 49/4 - (7/2)^2 = 0
- complete the square
4((x-7/2)^2)= 0
- bring the 4 back and you’re done.
hope this helped :)
