Answer:
see explanation
Step-by-step explanation:
He has incorrectly added/ subtracted the numerators/ denominators directly
To add/ subtract fractions we require them to have a common denominator
(a)
[tex]\frac{1}{3}[/tex] + [tex]\frac{3}{5}[/tex]
The lowest common multiple of 3 and 5 is 15
Change fractions to this denominator by multiplying numerator/denominator by the relevant value.
= [tex]\frac{1(5)}{3(5)}[/tex] + [tex]\frac{3(3)}{5(3)}[/tex]
= [tex]\frac{5}{15}[/tex] + [tex]\frac{9}{15}[/tex]
Now add the values on the numerators leaving the denominator
= [tex]\frac{5+9}{15}[/tex] = [tex]\frac{14}{15}[/tex]
------------------------------------------------------------------------------------
(b)
[tex]\frac{11}{12}[/tex] - [tex]\frac{5}{6}[/tex]
The lowest common multiple of 12 and 6 is 12
The first fraction already has a denominator of 12
Multiply the numerator/denominator of the second fraction by 2
= [tex]\frac{11}{12}[/tex] - [tex]\frac{5(2)}{6(2)}[/tex]
= [tex]\frac{11}{12}[/tex] - [tex]\frac{10}{12}[/tex]
= [tex]\frac{11-10}{12}[/tex] = [tex]\frac{1}{12}[/tex]
