解方程组x/4+y/3=7,2/3x+y/2=14,
问题描述:
解方程组x/4+y/3=7,2/3x+y/2=14,
答
x/4+y/3=7 ① 2/3x+y/2=14②
由①可得x/4+y/3=7由②可得2/3x+y/2=14
3x+4y=844x+3y=84
4y=84-3x3y=84-4x
y=(84-3x)÷4 y=(84-4x)÷3
(84-3x)÷4=(84-4x)÷3
3(84-3x)=4(84-4x)
252-9x=336-16x
7x=84
x=12 y=(84-3x)÷4=(84-3×12)÷4=12 ∴x=12,y=12