Answer:
y= - 9x+7
Explanation:
For problems like these, where you solve for a variable, you want to isolate y by add/sub or mult/div to get everything else to the other side of the equation symbol.
So for example, "9x" is an addition because it is getting added to y. Because of this, you are going to subtract it from both sides of the equation symbol. You will get y=-9x+7. Since 7 is positive, it will be added.