Question

with using identity (x+5)(x+8)

Answer 1

5xyz2 – 3zy                                          (ii) 1 + x + x2

(iii) 4x2y2 – 4x2y2z2 + z2                           (iv) 3 – pq + qr – rp

(v)                                           (vi) 0.3a – 0.6ab + 0.5

Answer 2

Heya..

(x+5)(x+8)
= x^2+(5+8)x+(5)(8)

[ by the identity,
(x+a)(x+b) = x^2 + (a+b)x+ab]

So, x^2 + (13)x + 40
x^2 + 13x + 40