When solving the following system of equations by substitution what would be a correct first step? pls pls pls help

< 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⭐

51-50

step-by-step explanation:

,xzgv

step-by-step explanation:

; oqirjg'

a is the right answer