Exercise 72.Solve: x2−12x+27=0. x2−6x+8=0. x2−4=4x−7. 5x2−4x−1=0. 4x−3=2x−x2. 9x2−24x+16=0. 6x2−5x−1=0. 4x+3=x2+2x. 16x2−16x+3=0. 3x2−10x+3=0. x2−14x−51=0. 34x−x2−225=0. x2+x−20=0. x2−x−12=0. 2x2−12x=−10. 3x2+12x−36=0. (2x−1)2+9=6(2x−1). 6(9x2−x)=55(x2−1). 32−3x2−10x=0. 9x2−6x−143=0. xx−1−x−1x=32. 1x−2+2x+2=56. 5x+7x−1=3x+11.