First we will find out the values of a
a/4=b/7
a=4b/7
Now
(a-b)/b
{4b/7-b}/b
(4b-7b)/7b
-3b/7b
-3/7
Ii.First ,expand: 5(x-2)=32
5x-10=32
bring 10 to the other side (add it to 32)
5x=42
divide both sides by 5 to get x
x=42/5
x=8.4
iii.Expand 5+2(x+3)=21
5+2x+6=21
bring 5 and 6 to the other side
2x=21-5-6
2x=10 divide both sides by 2
x=5
= 6.25%
= 0.0625
= 625/10000
= 1/16