Question

Let f(x) = x^2 - 2x

a. Find and simplify f(5)
b. Find the value of x such that f(x)=3

Answer 1

a) f(5)= 5^2 -2•5= 25-10=15
b) x^2 -2x-3=0
(x-3)(x+1)=0 so
x=3 and x=-1 are the solutions