Question

use suitable identities to find the following (i)(x+3) (x-5). (ii)103×105. (iii)(x+2y+z)²​

Answer 1

Step-by-step explanation:

(i). (x+3) (x-5) = x^2 + (3 - 5)x + (3)(-5)

= x^2 -2x -15

(ii). 103 × 105 = (100 + 3) (100 + 5)

= (100)^2 + (3 + 5)×100 + (3)(5)

= 10000 + 800 + 15

= 10815

(iii). (x+2y+z)^2 = x^2 + (2y)^2 + z^2 + 2(x)(2y) + 2(2y)(z) +

2(z)(x)

= x^2 + 4y^2 + z^2 + 4xy + 4yz + 2zx