Question

一元二次方程配方x^2-7x+1=0 x^2-18=9x x^2-3x=52

Answer 1

x^2-7x+1=0

x^2-7x+(7/2)^2-(7/2)^2+1=(x-7/2)^2-45/4=0,即(x-7/2)^2=45/4

x^2-18=9x

x^2-18-9x=0即x^2--9x+(9/2)^2-(9/2)^2-18=(x-9/2)^2-9/4=0即(x-9/2)^2=9/4=(3/2)^2

x^2-3x=52

x^2-3x+(3/2)^2=52+(3/2)^2即(x-3/2)^2=217/4

我的答题到此结束,