Answer:
5y+69.50<90
Step-by-step explanation:
You can think of the number of gigabytes he will use as "y", since we don't know the number of gigabytes he will use. The flat cost of one month is $69.50.
You need to add those to calculate the complete cost. The inequality would use a less than sign because he needs to pay less than $90/month. It would not use an inequality sign with a line under it because the problem doesn't say he wants to use $90 or less.
You would solve using basic computation (subtraction and division). Hope this helped!
Let the number be x
The sum of 2 equal numbers is simply x+x or 2x.
So we solve for each
70% of 100=70
students who didn't buy lunch=100-70=30
some of the 70 left so that the students who bought lunch, are 60% of those who are left
we know that the students who didn't buy lunch didn't change number so therefor
100% of students left-60%=40%= students that didn't buy lunch=30 so
40%=30
20%=15
100%=75
there were 75 students lfet in the cafeteria
About three years. Hope it helps!