Besar sudut BAC adalah ... . A.82° B.70° C.65° D.50°

2x-42+5x+5=180
7x - 37 =180
7x= 180+37
7x= 217
x=217/7
x= 31

masukkan x ke B

2x-42 = 2(31)-42 =62 - 42 = 20

180= A + B + C
180= A + 78 + 20 = A + 98
180=A+98
A=180 - 98 =82