Science and Mathematics for Engineering 6th Edition by John Bird

Exercise 13

Simplify:
(a) $\frac { 3 } { 4 } - \frac { 7 } { 15 }$
(b) $1 \frac { 5 } { 8 } - 2 \frac { 1 } { 3 } + 3 \frac { 5 } { 6 }$