Help me what is D please help ASAP

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

Amanda went into the grocery business starting with five stores. after one year, she opened two more stores. after two years, she opened two more stores than the previous year. if amanda expands her grocery business following the same pattern, which of the following graphs represents the number of stores she will own over time?

If a line is defined by the equation y = 5x + 2, what is the slope?