1-0.3(y-2)=(x+1)/5和(y-3)/4=(4x+9)/20-1.
问题描述:
1-0.3(y-2)=(x+1)/5和(y-3)/4=(4x+9)/20-1.
答
1-0.3(y-2)=(x+1)/5
(y-3)/4=(4x+9)/20-1.5
5-1.5y-3=x+1
4y-12=4x+9-30
x+1.5y=1
4x-4y=9
4x+6y=4
4x-4y=9
6y-4y=4-9
y=-2.5
x=1-1.5y=1-1.5*(-2.5)=4.75