17.5x+1.5×2.6=9.9
4.5x+4(x-2.5)=32.5
18-2(3-4x)=10x
17.5x=9.9-3.9
x=12/35
4.5x+4x-10=32.5
8.5x=42.5
x=5
18-6+8x=10x
2x=12
x=6