What is the output of the fuction f(x)=x+21 if the input is 4

How do you write something in scientific notation?

Can some one explain this i got sent this. is this a threat i’m scared

For the quadratic function [tex]y=(x+4)^2-1[/tex] , do the following: a) rewrite the function in the standard form, b) rewrite the function in intercept form, c) find the vertex, d) find the y-intercept, e) find the x-intercepts.