2.5x-3.2=7.8-2.6解:2.5x-3.2=5.22.5x=5.2+3.22.5x=8.4x=3.36
(7.8-2.6)+3.2=2.5XX=3.36
列式为:2.5x-(7.8-2.6)=3.2 2.5x-5.2=3.2 2.5x=8.4 x=8.4÷2.5 x=3.36