Question

(1)x=5-3y 3x-6y=6 (2)m-3n=-5 5m+2n=26 用带入法解方程.

Answer 1

(1)把x=5-3y 代入3x-6y=6中消去x得：3(5-3y)-6y=6;

即：15-9y-6y=6; -15y=-9; y=9/15=3/5;

x=5-3y=5-9/5=16/5;

所以圆方程组的解为：x=16/5; y=3/5;

(2))m-3n=-5得：m=3n-5代入5m+2n=26中得：5(3n-5)+2n=26;

15n-25+2n=26; 17n=51; n=51/17=3;

m=3n-5=9-5=4;

所以原方程组的解为：m=4;n=3