GRE Sample Test 1 Quantitative Reasoning 2

First, solve for x using the equation $\frac{7\mathit{y}}{2\mathit{x}}$ = 7. Cross multiply to find that 7y = 14x. Dividing both sides by 14 yields $\frac{1}{2}$ y = x.
Substitute this expression into the first equation to get $3\left(\frac{1}{2}\mathit{y}\right)$ + 2y = 24.
Combine the like terms to get $\frac{7}{2}\mathit{y}$ = 24; multiply both sides by $\frac{2}{7}$ to find y = $\frac{48}{7}=6.8$.