1、两边乘100+X15=0.12(100+X)100+X=12.5X=-87.52、300X+250Y=375 12X+10Y=15 (1)200X+150Y=64020X+15Y=64 (2)(2)×2-(1)×350X-36X=8314X=83X=83/14Y=(15-12X)/10=-393/70
写的太乱
