Six more than five times a number is at least twenty-one

Lets say the number is x so we can make an equation
If is at least 21, that means it has to be greater then or equal to it.
6+5*x>=21
You can subtract 6 from both sides
5*x>=15
Then divide both sides by 5
x>=3
You can conclude that the number is greater then or equal to 3.

y = 2

Step-by-step explanation:

If someone gives you an function that says f(x) = x + 2, that is the same thing as saying y = x + 2. The f(x) part is just to represent that it is a function of x.