In the following exercises, determine if the following points are solutions to the given system of equations.
$\left\{\begin{array}{l}x+y=2 \\ y=\frac{3}{4} x\end{array}\right.$
(a) $\left(\frac{8}{7}, \frac{6}{7}\right)$
(b) $\left(1, \frac{3}{4}\right)$