james has a job with a current salary of $42,000. he wants to earn a collage degree that will take him 2 years to complete and it will cost $28,000 per year. he will go to school full time and will not work. upon graduation, james' new salary will be $56,000 per year. how many years will it take james to recover his investment

Answer: 10.6 years

Step-by-step explanation:

The current salary is $42k per year

the college degree cost $28k per year, and with the degree he can win $56k per year, and here we also can consider that he "loses" the $42k tat he would have earned if he keeped working.

Then, the amount of money per year is:

m1 (y) = $42k*y

m2 (y) = - 2*$42k - 2*$28k + $56k*y

where y is the number of years after he gets his degree,

Now, we must find the value of y where those equations are equal:

$42k*y = - 2*$42k - 2*$28k + $56k*y = - 2 * ($28k + $42k) + $56k*y

($42k - $56k) * y = - 2*$60k = - $120k

y = 120k/14k = 8.6 years

but remember that we coun y after he gets his degree, which takes 2 years, so the actual number of years that he needs to recover his inversion is (8.6 + 2) years = 10.6 years

It will take him ten years.