How do i make (9x-7y=-7) into slope intercept form?

It's called "solve the equation for 'y' ". That means move things

around so that you end up with 'y' all alone on one side, and

everything else on the other side.

You started with 9x - 7y = - 7

Subtract 9x from each side: - 7y = - 9x - 7

Divide each side by - 7 : y = 9/7 x + 1