求解二元一次方程和三元一次方程,① {a/3+b/4=4/3 ②{2/3x+5/6=1 ③{2x+3y+8=6 {4(a+2)=3(b-4) {1/3x+1/6y=-1 {x-y+28=-1 {x+2y-8=5
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![求解二元一次方程和三元一次方程,① {a/3+b/4=4/3 ②{2/3x+5/6=1 ③{2x+3y+8=6 {4(a+2)=3(b-4) {1/3x+1/6y=-1 {x-y+28=-1 {x+2y-8=5](/uploads/image/z/6918814-46-4.jpg?t=%E6%B1%82%E8%A7%A3%E4%BA%8C%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E5%92%8C%E4%B8%89%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%2C%E2%91%A0+%7Ba%2F3%2Bb%2F4%3D4%2F3+%E2%91%A1%7B2%2F3x%2B5%2F6%3D1+%E2%91%A2%7B2x%2B3y%2B8%3D6+%7B4%EF%BC%88a%2B2%EF%BC%89%3D3%EF%BC%88b-4%EF%BC%89+%7B1%2F3x%2B1%2F6y%3D-1+%7Bx-y%2B28%3D-1+%7Bx%2B2y-8%3D5)
求解二元一次方程和三元一次方程,① {a/3+b/4=4/3 ②{2/3x+5/6=1 ③{2x+3y+8=6 {4(a+2)=3(b-4) {1/3x+1/6y=-1 {x-y+28=-1 {x+2y-8=5
求解二元一次方程和三元一次方程,
① {a/3+b/4=4/3 ②{2/3x+5/6=1 ③{2x+3y+8=6
{4(a+2)=3(b-4) {1/3x+1/6y=-1 {x-y+28=-1
{x+2y-8=5
求解二元一次方程和三元一次方程,① {a/3+b/4=4/3 ②{2/3x+5/6=1 ③{2x+3y+8=6 {4(a+2)=3(b-4) {1/3x+1/6y=-1 {x-y+28=-1 {x+2y-8=5
第一组
a/3+b/4=4/3
4a+3b=16标注为①
4(a+2)=3(b-4)
4a+8=3b-12
4a-3b=-20标注为②
①+②得8a=-4,即a=-1/2
①-②得6b=36,即b=6
第二组
2x/3+5/6=1
2x/3=1/6
x=1/4
将x=1/4代入另一个方程得
(1/3)(1/4)+y/6=-1
1/12+y/6=-1
y/6=-13/12
y=-13/2
第三组
2x+3y+8=6
整理得
2x+3y=-2标注为①
x-y+28=-1
整理得
x-y=-29 标注为②
①+②×3得5x=-89,即x=-89/5
将x=-89/5代入②中得y=-56/5
将x,y代入第三个方程验证x+2y-5=-89/5-56/5-5