Nicole and adam are each saving money for a car. the total amount of money nicole will save is represented by the function f (x) = 36 + 4x . the total amount of money adam will save is given by the function g (x) = x2 + 15. after how many weeks, x, will they have the same amount of money saved? explain how you arrived at your answer.
Accepted Solution
A:
For this case we have the following functions: f (x) = 36 + 4x g (x) = x2 + 15 By matching both functions we have: f (x) = g (x) 36 + 4x = x2 + 15 Rewriting we have: x2 + 15 - 4x - 36 = 0 x2 - 4x - 21 = 0 Solving the polynomial we have: (x-7) (x + 3) = 0 x = -3 x = 7 Taking the positive root we have: x = 7 Answer: They will have the same amount of money saved after: x = 7 weeks