If the tip was $9, you can find the total price by <u>dividing</u> 9 by .18. .18 is 18% but as a decimal (move to the left two decimal places). 9/.18 = 50.
You can also check the answer by finding the 18% tip of $50. 50*.18=9.
I am assuming theres an addition sign between the 3 and 4. So basically you want to multiply the 5x by both terms so it will end up being (5x•3) + (5x•4) Now simplify: 15x+20x Hope this helped ^_^