Answer:
Step-by-step explanation:
Let J = Joseph, K = Keith, m = number of months
We are told that Joseph weighs 120pounds and gains 10 pound each month.
From this we can write the following equation:
J = 120 + 10m
We also know Keith weights 150 pounds and gains 4 pounds each month, so:
K = 150 + 4m
Since we are trying to find how many months it will take for Joseph to weigh the same as Keith, this means we can say J = K
120 + 10m = 150 + 4m
Subtract 120 from both sides:
10m = 150 + 4m - 120
10m = 30 +4m
Subtract 4m from both sides:
10m - 4m = 30
6m = 30
Divide both sides by 6 to find "m".
m = 30/6 = 5
Therefore, it will take 5 months for Joseph and Keith to be equal weight.
