Answer:
see explanation
Step-by-step explanation:
(a)
Given
+ 
The common denominator is 15 ( the LCM of 3 and 5 )
Multiply numerator/ denominator of first fraction by 5
Multiply the numerator/ denominator of second fraction by 3
=
+
← add numerators , leaving denominator of 15
= 
= 
(b)
Given
- 
The common denominator is 8 ( the LCM of 8 and 4 )
Multiply numerator/ denominator of second fraction by 2
=
-
← simplify numerators leaving denominator of 8
= 
= 