if 16 g of a radioactive substance are present initially and 3 yr later only 8 g remain, how much of the substance will be present after 8 yr

< 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⭐

215.92 dollars is the answer

a reflection across the x-axis , followed by the by a reflection across the y-axis , and then a scale dilation of 0.5 .

70

step-by-step explanation: