Complete the proof using a two column proof

The vector matrix [2/7] is dilated by a favor of 1.5 and then reflected across the x axis. if the resulting matrix is [a/b] then a= and b=

Acoin bank containing only dimes and quarters has 12 more dimes than quarters. the total value of the coins is $11. how many quarters and dimes are in the coin bank?

How do you determine if an ordered pair is a solution to a given equation?