Question

gloria set aside $100 to buy school lunches for the year.each school lunch cost $2.the inequality 100-2x < can be used to find the number of school lunches gloria can buy before she has less than $20 left. what is the solution to this enuquality?

Answer 1

Inequalities

Since 100-2x is less than 20, this means that

100-2x < 20

We want to solve this inequality

We want to arrange it so the terms without x be on the left side of the inequality:

100-2x < 20

-20 + 100-2x < 20 - 20 [substracting 20 both side]

80 - 2x < 0 [ -20 + 100 = 80 and 20- 20 = 0]

80 - 2x < 0

We want to bring terms with x to the other side

100-2x < 0

100-2x + 2x < 2x [adding 2x both sides]

100 < 2x [-2x + 2x = 0

Now we have

100 < 2x

dividing both sides by 2:

100 < 2x

100/2 < 2x/2

50 < x

Answer: 50