a)49:7*x-13.2=14.8
49:7*x=14.8+13.2=28
7*x=49:28
7x=1.75
x=1.75:7
x=4
b)11+10x=61
10x=61-11=50
10x=50
x=50:10
x=5
c)5+x=456.7
x=456.7-5
x=451.7
d)1+2+...50=
50x51:2=2250:2=1275
1275*x-123.4=3701.6
1275*x=3701.6+123.4
1275*x=3825
x=3825:3
x=3
e)5.75+4+3x=16.05
9.75+3x=16.05
3x=16.05-9.75
3x=6.3
x=6.3:3
x=2.1