Posted by Kendra on .
Shelby's test scores are 99, 91, and 85. If she must average at least 90 points to get an A in the class, what must she earn on the next test?
Okay so this was my equation but it came out completely wrong.
99+91+85+x greater than or equal to 90
So what should the equation be?

Inequalities 
Jen,
You're very close but you left out one thing. You have to divide to find averages, so:
(99+91+85+x)/4>=90
99+91+85+x=360
Take it from here.