你好,emilytbaw
2/5x-1/3y+1=0
2x+2y=7
解:
整理,得
6x-5y+15=0 ①(方程两边同时乘以15)
2x+2y=7 ②
②×3,得
6x+6y=21 ③
③-①,得
11y=36
解得y=36/11
把y=36/11代入②中,得
2x+2×(36/11)=7
2x=5/11
解得x=5/22
∴这个二元一次方程组的解是:x=5/22,y=36/11
用加减消元法:①×15-②×3消去x,得y=36/11. 将y代回①式或②式,得x=5/22.