Question

Markus scored 85, 92, 82, and 94 on the first four tests of the semester. His teacher has not yet told him his score on his fifth test, but did tell him that his score on the fifth test is five points lower than the average (arithmetic mean) of all five tests. Which equation could Markus use to determine the score of the fifth test, x? O 4(x+5) = 353 + x O 5(x + 5) = 353 + x O 4(x - 5) = 353 + x O 5(x - 5) = 353 + x​

Answer 1

5(x + 5) = 353 + x

Explanation:

Answer 2

The answer would be 5(x+5)=353+x

Since x is his unknown score the average of all his scores is (353+x)/5

We know he got 5 less than his average so we would end up with the equation x=[(353+x)/5]-5

To put it in the format of the options given you would need to move the subtracted 5 to the left side by adding 5 to both sides and the result would be x+5=(353+x)/5

Then you would multiply the 5 to cancel it out leaving you with 5(x+5)=(353+x)