Each year, the Department of Water Works measures the chloride concentration level in the water. The first year, they found the chloride concentration changed by −135 mg/L . It is estimated that the chloride concentration will change −2115 mg/L the next year. What is the total change that will likely occur in 2 years?

Complete question :

Each year, the Department of Water Works measures the chloride concentration level in the water. The first year, they found the chloride concentration changed by −1 3/5 mg/L . It is estimated that the chloride concentration will change −2 1 /15 mg/L the next year. What is the total change that will likely occur in 2 years?

- 3 2/3 mg/L

Step-by-step explanation:

Given that:

Change in concentration during first year = - 1 3/5 mg/L

Estimated change in second year = - 2 1/15 mg/L

Total change in concentration likely to occur over the 2 years:

This will be the sum of the concentration in the first and second year:

[-1 3/5 + (-2 1/15)] mg/L

-1 3/5 - 2 1 /15

-8 / 5 - 31 /15

L. C. M of 5 and 15 = 15

(-24 - 31) / 15

= - 55 / 15

= - 3 10/15

= - 3 2/3 mg/L