When x = 3, the function f(x) = x² + 3x − 7 has a value of 11.
To find the value of the function when we are given a certain value of x, we need to substitute the value of x (in this case 3) wherever we see it in the function, and then simplify the function like always.
In this function, x appears 2 times, in x² and 3x. Substituting x = 3, we get:
f(x) = (3)² + 3(3) - 7
Now we simplify using the order of operations. Exponents:
f(x) = 9 + 3(3) - 7
Multiplication
f(x) = 9 + 9 - 7
Addition and subtraction
f(x) = 11
That means that f(x) = 11 when x = 3.
