
Doug C. answered 08/20/22
Math Tutor with Reputation to make difficult concepts understandable
Let J = amount of money John was given
Let N = amount of money Nat was given
Let x = #of days for John to spend all but $2500 and Nat to spend it all
Let y = #of days for John to spend all but $1000 and Nat to spend it all
J - 50x = 2500 (John spends $50 a day for x days and still has $2500 left)
N - 100x = 0 (Nat spends $100 for same number of days as John, but has spent it all)
J - 100y = 1000 (etc.)
N - 50y = 0
Solve the equations involving N for N:
N = 100x
N = 50y
Using those expressions substitute back into the equations involving J to get two equations involving J and N.
J - N/2 = 2500 (this is because when N = 100x, N/2 = 50x)
J - 2N = 1000 (this is because when N = 50y, 2N = 100y)
Multiply 1st equation by 2 to clear the fraction:
2J - N = 5000
J - 2N = 1000
Now you have a system of two equations two unknowns use either substitution or addition/elimination to solve for J and N. I would probably use the 2nd equation to get to: J = 2N + 1000 and replace J in the 1st equation to reach:
2(2N + 1000) - N = 5000
Continue from there to solve for N, then substitute resulting value into J = 2N + 1000 to solve for J.
Do a check to make sure the answers make sense. This would include also solving for x and y.