Sam must have an average of 70 or more in his summer course to obtain a C average his first grades were?

75,63,and 68 write an inequality representing the the score that he must get on his last test to get a C grade.

Sam must have an average of 70 or more in his summer course to obtain a C average his first grades were?
based on the definition of what an average is, you know that the sum of all his grades divided by the number of grades has to be at least 70. the unknown "X" represents what the last score must be. so the equation looks like this:





(75+63+68+X)/4 %26gt;[or=to] 70





to isolate the variable, multiply by 4


75+63+68+X %26gt; 280





simplify the left, then subtract from each side


206+X %26gt; 280


X %26gt; 74





so sam has to get at least a 74! the end! :)
Reply:He needs 62.
Reply:(206+x)/4 =OR%26gt; 70
Reply:Yes, the answer is "he must get more than 74 in his last test to get a C grade"
Reply:(75 + 63 + 68 + x) / 4 %26gt;=70





From there, multiply both sides by 4 and simplify to:


206 + x %26gt;= 280


x %26gt;= 74