yg jago mtk bantu yaaa boc=2x+5°

besar sudutnya 90 derajat
mencari x
2x+5'+3x-15' = 90'
5x = 90'+10
5x = 100
x = 100 : 5 = 20

sudut BOC = 2 (20) + 5
= 40 + 5
= 45 (C.)

smoga membantu