When denominators are the same, add the numerators and keep the denominator. Then simplify.

All fractions have the same denominator (12). Add the numerators.
Sum	=	\(\dfrac{7}{12} + \dfrac{7}{12} + \dfrac{7}{12} = \dfrac{21}{12}\)
Simplify: GCD(21, 12) = 3.
Simplified	=	\(\dfrac{21 \div 3}{12 \div 3} = \dfrac{7}{4}\)
Convert to a mixed number: 7/4 = 7 divided by 4 = 1 whole and 3/4.
As mixed number	=	\(1\dfrac{3}{4}\)