数学一道计算题2x+3y-4z=-7 ①x-4y/3=2y+3z/2=2 ②

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数学一道计算题2x+3y-4z=-7               ①x-4y/3=2y+3z/2=2      ②

数学一道计算题2x+3y-4z=-7 ①x-4y/3=2y+3z/2=2 ②
数学一道计算题
2x+3y-4z=-7 ①
x-4y/3=2y+3z/2=2 ②

数学一道计算题2x+3y-4z=-7 ①x-4y/3=2y+3z/2=2 ②
∵x-4y/3=2y+3z/2=2
∴x=2+4/3y,z=4/3-4/3y
由①得
4+8/3y+3y-16/3+16/3=-7
∴y=-17/33
x=130/99
z=200/99

此解集为一条直线

x-4y/3=2y+3z/2=2
x=2+4y/3
z=(4-4y)/3
2x+3y-4z=-7
2*(2+4y/3)+3y-4(4-4y)/3=-7
y=5/11
x=86/33
z=8/11

x=-130/99
y=-17/33
z=200/99

由②
x=2+4y/3
z=4/3-4y/3
代入①
4+8y/3+3y-16/3+16y/3 = -7
解得y=-17/33
则x=130/99,z=200/99
即方程组的解为x=130/99,y=-17/33,z=200/99

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