解:45x + 180=75x - 300180 + 300=75x - 45x480=30xx=480÷30x=16
45×(x+4)=75×(x–4)x+4=5/3(x–4)x–5/3x=-20/3-4-2/3x=-32/3x=16
45×(x+4)=75×(x–4)解:x+4=5/3(x–4)x–5/3x=-20/3-4-2/3x=-32/3x=16