Incorrect. The information gives you two equations:

(A) $\displaystyle{y}={x}-{14}\usepackage{cmbright}\Huge\$

(B) $\displaystyle\frac{{{x}+{y}}}{{2}}={84}\usepackage{cmbright}\Huge\$

Substitute $\displaystyle{x}-{14}\usepackage{cmbright}\Huge\$ for y in (B). Simplify and solve for x. Then substitute that value into (A) to get the value of y.

The correct answer is 77.