{x+y=10 2x-3y+2z=5 x+2y-z=3急啊!
问题描述:
{x+y=10 2x-3y+2z=5 x+2y-z=3急啊!
答
x+y=10 (1)2x-3y+2z=5 (2)x+2y-z= 3 (3)(3)*2:2x+4y-2z=6 (4)(2)+(4):4x+y=11 (5)(5)-(1)3x=1x=1/3 (6)把(6)代入(1)y=29/3 (7)把(6)和(7)代入(3)z=50/3所以原方程组的解是:x=1/3y=29/3z=50/3...