Factorise the following.​

iii. (p - 7)(p - 3)

iv.(x - 8)(x + 4)

Step-by-step explanation:

iii. p² - 10p + 21

= p² - (7 + 3)p + 21

= p² -7p -3p + 21

= p(p - 7) - 3(p - 7)

= (p - 7)(p - 3)

iv. x² - 4x - 32

= x² - (8 - 4)x - 32

= x² - 8x + 4x - 32

= x(x - 8) + 4(x - 8)

= (x - 8)(x + 4)

step-by-step explanation:

< 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⭐