(1)(0.5+x)+x=9.8÷2 0.5+2x=4.9 0.5+2x-0.5=4.9-0.5 2x=4.4 2x÷2=4.4÷2 x=2.2 (2)2(x+x+0.5)=9.8 2x+2x+1=9.8 4x+1-1=9.8-1 4x=8.8 4x÷4=8.8÷4 x=2.2 (3)25000+x=6x 25000+x-x=6x-x 5x=25000 5x÷5=25000÷5 x=5000 (4)3200=440+5x+x 6x+440=3200 6x+450-450=3200-440 6x=2760 6x÷6=2760÷6 x=460 (5)x-0.8x=6 0.2x=6 0.2x÷0.2=6÷0.2 x=30 (6)12x-8x=4.8 4x=4.8 4x÷4=4.8÷4 x=1.2 (7) 7.5+2x=15 2x+7.5-7.5=15-7.5 2x=7.5 x=3.75