用适当的方法解方程1.4(x-3)^2+x(x-3)=0
问题描述：
用适当的方法解方程1.4(x-3)^2+x(x-3)=0
2.(5x-1)^2-2=0
3.3y^2-4y=0
4.x^2-7x-30=0
答
1.4(x-3)^2+x(x-3)=0(x-3)(4x-12+x)=0(x-3)((5x-12)=0∴x=3 x=12/52.(5x-1)^2-2=0(5x-1)²=2∴5x-1=±√2∴x=(1+√2)/5 x=(1-√2)/53.3y^2-4y=0y(3y-4)=0∴y=0 y=4/34.x^2-7x-30=0(x-10)(x+3)=0x=10 x=-3