解方程,求t,写下过程 (x+y)t=(1.2x+y)*0.9t=(x+0.75y)(t+2.5)
问题描述:
解方程,求t,写下过程 (x+y)t=(1.2x+y)*0.9t=(x+0.75y)(t+2.5)
答
t=20,由(x y)t=(1.2x y)*0.9t可得y=0.8x
由(x y)t=x 0.75y)(t 2.5)可得t=20