how to find equations in one variable?

2 ⤊

a student earned scores of 87 81 88 on the first 3 of 4 test to keep the average of 87 what should he get on the fourth test

2007-04-21 19:27:18 · 3 answers · asked by tiara s 1 in Science & Mathematics ➔ Mathematics

(87 + 81 + 88 + X ) / 4 = 87
256 + X = 348
X = 348 - 256
X = 92

thus, this students should get 92.

2007-04-21 19:34:02 · answer #1 · answered by gwennie 3 · 1⤊ 0⤋

Let required score be x
87 = (87 + 81 + 88 + x) / 4
348 = 256 + x
x = 92
He requires 92 in 4th test.

2007-04-22 03:27:08 · answer #2 · answered by Como 7 · 0⤊ 0⤋

87*4 = 348

348-87-81-88=92(your answer)

2007-04-22 02:32:17 · answer #3 · answered by Q-Diggity 1 · 1⤊ 0⤋