Make X the subject of the equation (9x-7)/3 = 8y

To start solving a question like this you want to do it in a set of steps:

Step 1: Get rid of the division.  To do thsi you need to do the opposite function.  The opposite of division is multiplication so you multiply both sides by what you've divided by (in this case 3).  So the equation would now read: 9x-7 = 24y

Step 2: Get 9X on it's own on   To do this you need to get rid of the -7.  The opposite function of subtraction is addition so you +7 to both sides.  So the equation would now read: 9x = 24y+7

Step 3: Get X on it's own.  9x means 9 multiplied by X so you use the opposite function again, In this case you would divde both sides by 9 to get x on it's own.  The equation would now read x = (24y+7)/9