Hey there!
When we are given what one of our variables is equal to, we can easily solve the system of equations via substitution, which is where we take the variable value, plug it into the other equation, and solve for the other variable.
In this case, we just take our value for y and plug it in for the value for y in the first equation and solve for x.
2(-x+7)=14-2x
-2x+14=14-2x
-2x=-2x
x=x
As we can see, there are infinitely many soultions to this first equation, which means that there is no possible way to solve for y because x has infinitely many solutions, so there are infinitely many solutions to this system of equations, because they are both the same line.
I hope this helps!
