Systems of Equations Practice Test

Two phone plans have costs (in dollars) given by $C_1=15+0.10m$ and $C_2=5+0.20m$, where $m$ is the number of minutes. For what value of $m$ do the plans cost the same?

A streaming service offers two plans. Plan A charges a $\$6$ base fee plus $$2$ per movie, and Plan B charges a $\$12$ base fee plus $$1$ per movie. Let $m$ be the number of movies watched in a month and $c$ be the total monthly cost (in dollars). At what ordered pair $(m,c)$ do the two plans cost the same?