SOLUTION: evan weighs 220 pounds. He wanted to weight less than 200 pounds. If he can lose an average of 2 pounds per month on a certain diet, how long should he stay on his diet to reach hi

Algebra ->  Inequalities -> SOLUTION: evan weighs 220 pounds. He wanted to weight less than 200 pounds. If he can lose an average of 2 pounds per month on a certain diet, how long should he stay on his diet to reach hi      Log On


   

Question 1204741: evan weighs 220 pounds. He wanted to weight less than 200 pounds. If he can lose an average of 2 pounds per month on a certain diet, how long should he stay on his diet to reach his goal weight?
Found 3 solutions by math_tutor2020, josgarithmetic, MathTherapy:
Answer by math_tutor2020(3817) About Me  (Show Source):
You can put this solution on YOUR website!

n = number of months
2n = number of pounds lost over those n months
220 = starting weight
220 - 2n = final weight
220 - 2n < 200
-2n < 200 - 220
-2n < -20
n > -20/(-2) .... inequality sign flip
n > 10

Another way to solve
220 - 2n < 200
220 < 200+2n
2n+200 > 220
2n > 220-200
2n > 20
n > 20/2 .... no sign flip this time
n > 10
The inequality sign only flips if dividing both sides by a negative number.


Answer: Evan needs to be on the diet for more than 10 months to reach his goal weight.

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
y=mx%2Bb
-
system%28b=220%2Cm=-2%2Cy=200%29

you want to solve for x.
He only wants to reach less than 200.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
evan weighs 220 pounds. He wanted to weight less than 200 pounds. If he can lose an average of 2 pounds per month on a certain diet, how long should he stay on his diet to reach his goal weight?

An EQUATION by one of the other 2 persons who responded, is WRONG! An INEQUALITY is RIGHT!