{x+y+z=3.3

问题描述:

{x+y+z=3.3
x/3+y/4+z/5=51/60
x/5+y/4+z/3=53.4/60
(解这个三元一次方程组,因为我不会,答案x=1.2 y=0.6 z=1.5
可以写明白点吗?我不懂

x+y+z=3.3 ① x/3+y/4+z/5=51/60 ②x/5+y/4+z/3=53.4/60 ③ ②式左右两侧同乘60得20 x+15y+12z=51 ④③式左右两侧同乘60得12x+15y+20z=53.4 ⑤⑤-④=z-x=0.3 ⑥①式左右两侧同乘15得15x+15y+15z=49.5 ⑦④-⑦= 5x...