If the city doubles the fee from $8 to $16, then payments to the city will

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

Can someone tell me if this is perpendicular? !

If you double the input of a function and it results in half the output, and if you triple the input and it results in a third of the output, what can be guessed about the function? check all that apply.