2x^2+9x-5=(2x-1)^2 4x^2+9x-5=2x^2+1^2-2*1*2x 4x^2+9x-5=4x^2+1-4x 4x^2+9x-4x^2+4x=1+5 13x=6/13 x=6/13
2x^2+9x-5=(2x-1)^2 4x2+ 9x-5=4x2-4x+1 4x2+9x-4x2+4x=1+5 13x=6 x=6/13