Mental math is something that can be done i your head.
for example you can do 1+1 in your head and you dont need a calculator or paper to do it so i would be called mental math
Hope this helps
remember if you ever need anything and you dont want to waste points you can just post it on my pfp or message me the question
The answer is B, the green is f(x)=x^2 and the red one is g(x)=f(2x).
Answer:

Step-by-step explanation:

Answer:
The first picture is a function and the second picture is not.
Step-by-step explanation:
Reason - In the first picture, there is no repeating value of x. In other words, every x value has a y value. However, in the second picture, the x value, 2 goes to 2 and -3.
(45 gal/day) x (31 day/Dec) =
(45 x 31) (gal/Dec) = <em>1395 gallons</em> per December .
Choice-B is closer to that figure than Choice-A is,
but they're both poor estimates.