A student has a 90, 84, and an 86 on there first 3 tests. What score would the student need to make on the 4th test to bring his test average up to 90?

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10

a c

step-by-step explanation:

answer is c

step-by-step explanation:

81/12=324/x

x=48

on plase n