As you can see both the expressions, x+2 and -4x+7 are equal to "y". That means they are equal to each other too.
So let's equal them and solve it.
[tex]x+2=-4x+7\\ \\ x+2+4x=7\\ \\ x+4x+2=7\\ \\ 5x+2=7\\ \\ 5x=7-2\\ \\ 5x=5\\ \\ x=\frac { 5 }{ 5 } \\ \\ x=1[/tex] Now we have x's value we will plug it in the first equation to find "y".