A new car depreciates as soon as you drive it out of the parking lot

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

Awoman has 14 different shirts: 10 white shirts and 4 red shirts. if she randomly chooses 2 shirts to take with her on vacation, then what is the probability that she will choose two white shirts? show your answer in fraction and percent, round to the nearest whole percent.

Me i’m stuck on all these questions besides the two bottom ones