(1)3x(x-2)+2(x-2)=0 (2)解方程:(x-根号2)=5x(根号2-x)
问题描述:
(1)3x(x-2)+2(x-2)=0 (2)解方程:(x-根号2)=5x(根号2-x)
答
(1)3x(x-2)+2(x-2)=0
(x-2)(3x+2)=0
x=2或x=-2/3
(2)解方程:(x-根号2)=5x(根号2-x)
(x-根号2)-5x(根号2-x)=0
(x-根号2)+5x(x-根号2)=0
(x-根号2)(1+5x)=0
x=根号2 或x=-1/5(x-根号2)(1+5x)=0这一步怎么来的提取公因式啊(x-根号2)(x-根号2)=5x(根号2-x)把5x(根号2-x)移到左边得:(x-根号2)-5x(根号2-x)=0从(根号2-x)提取一个负号,加上移过来后变成的负号,变为正号:(x-根号2)+5x(x-根号2)=0提取公因式(x-根号2)(1+5x)【这怎么说也不知道了,就是提取公因式(x-根号2)(1+5x)=0x=根号2 或x=-1/5