А)8-3/4=7 4/4-3/4=7 1/4
б)12-5 7/9=11 9/9-5 7/9=6 2/9
в)6 2/5-4 3/5=5 (5/5+2/5)-4 3/5=5 7/5-4 3/5=1 4/5
<span>225:(х-1)+130:26=30
225:(х-1)+5=30
225:(х-1)=30-5
225:(х-1)=25
25*(х-1)=225
25х-25=225
25х=225+25
25х=250
х=250:25
х=10</span>
125х5=625, В=1, А= 2, ...