Li has scores of 82.5, 84, 88.5, 92.5, and 94.5 on quizzes. what score must he get on the next quiz to have an average of at least 90?

98

Step-by-step explanation

First, we need to give the next test a variable since we don't know what it is yet. We will name it "x". Since you are trying to find the average, you will have to add all 6 tests together and then divide it by 6 since there are 6 quizzes.

The equation would be:

82.5+84+88.5+92.5+94.5+x   ≥ 90

                   6

Then, you should closely but not completely simplify that to:

442+x    ≥ 90

   6

Next, multiply each side by 6. Cancelling the "6" on the left:

442+x ≥ 540

Lastly, subtract 442 from each side of the equation. The 442 on the left cancels out, leaving x alone, and on the left, 540 minus 442 is 98:

x ≥ 98

Thus, Li has to earn at least a 98 on his next quiz in order to have an average of at least a 90.  :)

                                                   -Question answered by Angelina M.

                                                                                  8th grade student

answer: a and c are correct

step-by-step explanation:

the +5 is the vertical translation

the added negative symbol in front is the reflection over the y-axis

its a straight line parallel to the time axis