Question

a water tank holds 992 gallons but is leaking at a rate of 5 gallons per week . a second water tank holds 1,240 gallons but is leaking at a rate of 9 gallons per week . after how many weeks will the amount of water in the two tanks be the same

Answer 1

62 week

Explanation:

What we need is to represent the ratios in expression

For example if we have 992 gallons and the leaking is 5 gallons per week, the expression for the gallons after every week is

992-5x

x is the weeks

And the other case the expressions is

1240-9x

The question is the weeks for the amount being the same, then every equation can be equal to Y and it represent the same amount

992-5x=y

1240-9x=y

in both the y is the same, then

992-5x=1240-9x

992-1240=-9x+5x

-248=-4x

-248/-4=x

62=X

and that is the weeks we need for the amount being the same in both tanks