Name the values Of the 4s in the number 400,440

Which function families have maximums and minimums? 1.)linear absolute value functions and exponential functions 2.) linear absolute value functions and quadratic functions 3.) linear absolute value functions and linear functions 4.) linear absolute value functions and constant functions

We just started the introduction into circles and i have no idea how to do this.

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.