What is $500= blank+ $600

-100$

Step-by-step explanation:

Adding a negitive number to a positive number is basically subtracting it, and since 600-100 is 500 that means 600 + -100 is also 500.

< 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⭐