Just replace all of the x’s with 5 and solve using order of operations. I will post what I got for my answer in the comments of the answer if you need it.
<span>how much heat energy did the light bulb give off? </span>21
The answer is 2:1 because at first your ratio would be 18:9 but if you divide that by 9 (for simplifying purposes) than its 2:1
