解方程组{ax+5Y=15;4x-by=-2

问题描述:

解方程组{ax+5Y=15;4x-by=-2

4aX+20Y=60
4aX-abY=-2a
20Y+abY=60+2a
Y=(60+2a)/(20+ab)
X=[-2+(60b+2ab)/(20+ab)]/4=-1/2+(30b+ab)/(40+2ab)