Which expression is equivalent to sin(2x) - sin(x)

Which expression is equivalent to 8(k + m) − 15(2k + 5m)?

Me! i really need to get this right before 9. prove the divisibility of 7^6+7^5-7^4 by 11. use factoring so you get a number times 11. just tell me the number. i need this done asap

With both problems. a.s.a.p directions on photo ^