Naomi works in a music shop and earns $42 per day. She earns an extra $2 for each CD she sells. If Naomi wants to earn at least $80 per day, which inequality shows the minimum number of CDs, n, that she should sell? A. 42 + 2n ≤ 80, so n ≤ 19 B. 42 + 2n ≥ 80, so n ≥ 19 C. 42 + 2n ≥ 80, so n ≥ 36 D. 42 + 2n ≤ 80, so n ≤ 36
Can you help?
the key word here is "at least" which implies that she wants to earn at "the least" $80 per day So: \(\ge 80\)
she is already earning 42, so you can just stick that into the equation
Then what do I do, I don't understand how to do this kind of math.
it's fine :) Then, you would use the variable "n" to represent the amount of cd's; the 2 coefficient before "n" represents how much each cd sold earns you ($2). Therefore, your equation is: 42+2n \(\ge 80\)
then solve the inequality and find out how many cd's that the person must sell in order to earn AT LEAST 80 dollars a day. Try this on your own, but I will guide you along the way if you need
So how do I do it?
Solve this like a regular equation.
like so: 42+2n \(\ge 80\) 1.) subtract 42 from both sides: 42+2n \(\ge 80\) -42 -42 ---------- 2n \(\ge 80\) 2.) divide 2 from both sides
from here: 2n \(\ge 80\), can you solve for me?