Quanto e 16 elevado a menos 1 sobre 2 ,explicacao

Parks is wearing several rubber bracelets one third of the bracelets are tie-dye 1/6 are blue and 1/3 of the remainder are camouflage if parks wears 2 camouflage bracelets how many bracelets does he have on

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great

Which expression is equivalent to (5x^7+7x^8) − (4x^4−2x^8)? a. 9x^8 + 5x^7−4x^4 b. 3x^8 + 7x^7 c. 12x^8 − 2x^4 d. 5x^8 + 5x^7 + 4x^4