解方程 7x^2+2x=0 x^2=(2x-5)^2 49x^2-25=0 4x^2=8x 今天就要

解方程 7x^2+2x=0 x^2=(2x-5)^2 49x^2-25=0 4x^2=8x 今天就要
解方程 7x^2+2x=0 x^2=(2x-5)^2 49x^2-25=0 4x^2=8x 今天就要

解方程 7x^2+2x=0 x^2=(2x-5)^2 49x^2-25=0 4x^2=8x 今天就要
7x^2+2x=0 => x(7x+2)=0 =>x1=0, x2=-2/7
x^2=(2x-5)^2 =>2x-5=+/- x =>x1=5, x2=5/3
49x^2-25=0 =>x^2=25/49 =>x1=5/7, x2=-5/7
4x^2=8x =>4x(x-2)=0 =>x1=0, x2=2
怎么样?够详细吧?哈哈