一副三角扳按如图方式摆放，且∠1的度数比∠2的度数大50°，若设∠1＝x°，∠2＝y°，则可得到方程组为  (     )

A：$\left\{\begin{array}{c}x=y-50\\ x+y=180\end{array}\right.$

B：$\left\{\begin{array}{c}x=y+50\\ x+y=180\end{array}\right.$

C：$\left\{\begin{array}{c}x=y-50\\ x+y=90\end{array}\right.$

D：$\left\{\begin{array}{c}x=y+50\\ x+y=90\end{array}\right.$