Subtract.

3 x + z + 9
3 x - 16 y - z + 9
3 x - z + 9

3x-16y-z+9

Step-by-step explanation:

That’s as simple as it can get because

8x-5x = 3x

-8y-8y= -16y

-z

+9

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐