Recall that the slope formula is y=mx+b (m is the slope)
You need to first get y by itself, to do that you subtract 9x on both sides of the equation
9x+7y=10 subtract 9x to the left side where it will cancel it because you're adding a positive to a negative number that are the same, then you subtract 9x to the right side of the equation
when you do that you should get: 7y= -9x+10
Now you divide 7 on both sides
you then should get: y= -9/7x-10/7