To solve using completing square method we proceed as follows: x^2-10x+8=0 x^2-10x=-8 but c=(b/2)^2 c=(10/2)^2=25 thus we can add this in our expression to get x^2-10x+25=8+25 factorizing the LHS we get: (x-5)(x-5)=33 (x-5)^2=33 getting the square roots of both sides we have: x-5=+/-√33 x=5+/-√33
