2) Does the mapping diagram show a function?*

No

Step-by-step explanation:

In order for it to be a function, every input (x values on the left) needs to be paired with only 1 output (y values on the right). Notice that 1 is paired with both 2 and 4.  This means it is not a function, but it is paired with two different values.

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.