Solve Each System by Using Either the Substitution or the Elimination-By-Addition

Multiple Choice

Solve each system by using either the substitution or the elimination-by-addition method, whichever seems more appropriate. $$\left( \begin{array} { c } \frac { 3 x } { 4 } - \frac { 2 y } { 3 } = 84 \\\frac { 7 x } { 6 } + \frac { y } { 5 } = 75\end{array} \right)$$

A) ( 72, $-$ 45)
B) ( 72, 45)
C) ( $-$ 72, $-$ 45)
D) no solutions
E) infinitely many solutions