Let x be the score of the 3rd quiz,, then the average score will be:
(83+91+x)/3, which = (174+x)/3. but this average should be greater or equal to 85 and smaller or equal to 90:
85 ≤ (174+x)/3 ≤ 90
1st multiply all terms with 3 → 255 ≤(174+x) ≤ 270
2nd subtract 173 from all terms → 255-174 ≤174-174+x ≤270-174
81 ≤ x ≤ 96
Answer:
2
Step-by-step explanation:
Answer:
x=4
Step-by-step explanation:
first lets move it over
3x = 12
x=4
check:
14*4 = 56
-5 =
51
7+ 11x=
11*4 = 44
44+7 = 51
51 = 51
hope this helps :D
