math
posted by Carolyn on .
jim has grades of 84, 65, 76 on three tests. what grade must he obtain on the next test to have an average of exactly 80% for all four tests?

84 + 65 + 76 = 225
0.8 * 400 = 320
320  225 = 95 
( 84 + 65 + 76 + x ) / 4 = 80
84 + 65 + 76 + x = 4 * 80
225 + x = 320
x = 320  225 = 95 
(65 + 84 + 76 + x ) / 4 = 80
(Balance the Equation)
225 + x = 320 [65 + 84 + 76 + x = 320]
(Balance the Equation)
x = 320  225 = 95 
y=5x3 y=3x+13

The sum of two consecutive numbers is 37. What are they