(1)2x+5x=0.....①
x+3y=1 .....②
①-②×2得:
-y=-2
y=2 .....③
③代入②得:
x+6=1
x=-5
解为:
y=2
(2)1.5p-2q=-1.....①
-4.5p+7q=8 ...