解方程组{4分之2x-3y+5分之2(x+2y)=1{4分之3(2x-3y)-5分之x+2y=-4

2024-12-15 00:20:34
推荐回答(1个)
回答1:

(2x-3y)/4+2/5(x+2y)=1
3/4(2x-3y)-(x+2y)/5=-4
令 2x-3y =m x+2y = n 则:
m/4 +2n/5 = 1 ……①
3m/4 -n/5 = -4 ……②
①+②×2 得
7m/4 = -7
m= -4
n = 5
得新方程组:
2x- 3y =-4 ……③
x+2y = 5 ……④
④×2 - ③ 得
7y = 14
y = 2
x = 1