3x-5y=-9 2x+7y=-6
1个回答
3x-5y=-9
所以x=(5y-9)/3
代入2x+7y=-6
2(5y-9)/3+7y=-6
10y-18+21y=-18
31y=0
y=0
x=(5y-9)/3=-3
相关问题
2x-3y-2=0 5x+3y=18 2x-3y=7 (2x-3y+5)/7+2y=9 2x-3y=3 6x+5y=35
求解(1){2x-y=9 3x+y=7 (2){4x-3y=5.6 5x+3y=7.4 (3){2x+3y+19=0 x
3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y
2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
解方程组[5x-(1-11y)]/8=(5y-6x+2)/9=(3x+4y+7)/6
X+2y=o 3X+4y=6 方程组 要过程还有5X+6y=16 7X-9Y=5
2X+4y+3z=9 3x-2y+5z=11 5x-6y+7z=13
(7x-2y)(3x-2y-1)-(4x+3y)(9x+6y)
解三元一次方程:3x+4z=7 2x+3y+z=9 5x-9y+7z=-6
1:7x+2y-z=7 2:6x-y+z=7 3:4x+3y+z=9 1:9x+4y+z+10 2:-9X+2y+3z=