解方程x=420-x
问题描述:
解方程x=420-x
答
x=420-x
2x=420 两边同时加上x
x=210 两边同时除以24x-120=3(100-x)等于多少 请详细4x-120=3(100-x)4x-120=300-3x7x-120=3007x=420x=60