Q:

Lisa and Joey are each saving money for their prom. Lisa’s total amount of money is represented by the function f(x)=20-13x. The total amount of money Joey has is given by the function g(x)=x^2-10. After how many weeks, x, will they have the same amount of money saved? Show your work.

Accepted Solution

A:
Answer:2 weeks Step-by-step explanation:Given in the question that,Equation that represent Lisa's total amount of money f(x) = 20 - 13xEquation that represent Joey's total amount of money g(x) = x² - 10To find weeks, x, after which they will have same amount of money, we will equate both equation 20 - 13x =  x² - 10 x² - 10 - 20 + 13x = 0 x² - 30 + 13x = 0 x² + 13x - 30 = 0 (x - 2)(x + 15) = 0 x = 2 or x = -15Weeks, x, can not be negative so we will reject x = -15Hence, after 2nd week Lisa and Joey will have the same amount of money save.