angela's average for 6 math tests is 87. on her first four test she had scores of 90 , 87, 82 , and 89. on her last test , she scored 14 points lower than she did on her fifth test. what scores did angela receive on her 5th and 6th test?

Question

agreene · Answer

(90+87+82+89+x+[x-14])/6  = 87             you get this because the arithmetic mean is the sum of the parts divided by how many parts, and it tells you it = 87. Then we just solve... start by combining like pairs and get:
(334+2x)/6 = 87         multiply both sides by 6
334+2x = 522             subtract your 334
2x = 188                     divide by 2
x = 94                          now we know on the 5th test, she got a 94.  and since the 6th test is 14 less... 94-14 = 80  on her 6th test.

anonymous · Answer

the sum of her 4 math test scores is: 87*6=522
so 522=90+87+82+89+x+x-14
solve the equation