'Solve for y' means that you have to clear 'y' from the equation:
[tex]y+2x=5[/tex]Clearing 'y':
[tex]y=5-2x[/tex]Now, to find the value of 'y' for each value of 'x' you just have to replace 'x' in the expression above by each of the given values. This is:
For x = -1
[tex]y=5-(2\times(-1))[/tex][tex]y=5+2=7[/tex]When x = -1, y = 7.
For x = 0:
[tex]y=5-(2\times0)[/tex][tex]y=5-0=5[/tex]When x = 0, y = 5
For x = 3:
[tex]y=5-(2\times3)[/tex][tex]y=5-6=-1[/tex]When x = 3, y = -1
