write your answer as an inequality thanks!

Question

the average of nora's two test scores must be 80  or more for her to get at least a b in the class.she got a 72 on her first test. what grades can she get on the second test to make at least a b in the class 

Answer 1

Remember that an average is the sum of the elements divided by the total elements in a series.  

 

In this case it's (test1 + test2) / 2, because there are two tests.  

 

We know one test is a 72. Let's say that's test1.  Our equation becomes (72 + test2) / 2 is greater than or equal to, which I'll write '>=' 80.  We want it greater than or equal to 80 because it's "at least" a B, but could be higher.  

 

So our equation is now

(72 + test2) / 2 >= 80

 

Slove for test2 

 

72 + test2 >= 160

test2 >= 88

 

Check

 

(72 + 88) \ 2 = 80 (true)

Therefore, any number greater than 88 will raise the score higher than 80.