Help this is math grade10 helppp

Both are rational.

Step-by-step explanation:

a. 4/7 + (-1/3) = 5/21 which is rational

b. √4 x 2/5 = 4/5 which is rational

< 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⭐