Find all fixed points for the function by setting the function equal to x and solving the resulting equation for x.
-Susan is 7 years older than her brother Bob. If the product of their ages is 638 $\text { how old is Susan }$
A) 7
B) 29
C) 22
D) 30

Question

Quizplus · Accepted Answer

Let's start by setting up an equation to represent the problem. Let x be Bob's age, then Susan's age would be x+7. The product of their ages is 638, so we have the equation x(x+7) = 638. Simplifying this equation, we get x^2 + 7x - 638 = 0. We can use the quadratic formula to solve for x, but notice that 638 can be factored into 2*11*29. Since Bob and Susan's ages must be integers, we can try different values of x that satisfy the equation. We can see that x=22 is a solution since 22*29 = 638. Therefore, Bob is 22 years old, and Susan is 29 years old. The answer is B).

Find All Fixed Points for the Function by Setting the Function