The zero of a function is an x-value that makes a function evaluates to zero when the x-value is substituted into the function.
A zero of a function is always a value located on the x-axis of a coordinate system.
1.
The zero of the linear function f(x) = 5x + 10 is x = -2
5(-2) + 10 = -10 + 10 = 0
2.
The zeros of f(x) = x2 - 16 are x = 4 and x = -4
42 - 16 = 16 - 16 = 0
(-4)2 - 16 = 16 - 16 = 0
Notice that it is not possible to find the zeros of the exponential function f(x) = ex
No matter what number you replace x with, you could never get the exponential function to evaluate to zero.