Question

Evaluate by using suitable identity.

(mention the identity used for each question).

i) (203)²

ii) (30.9) x (29.1) ​

Answer 1

$\to \tt {(203)}^{2} \\ \\ \to \tt{(200 + 3)}^{2} \\ \\ \to \tt{(200)}^{2} + {(3)}^{2} + 2(200)(3) \\ \to \tt40000 + 9 + 1200 \\ \to \sf \green{41209}$

And,

$\to \tt(30.9) \times (29.1) \\ \\ \to \tt (30 + 0.9) \times (30 - 0.9) \\ \\ \to \tt {(30)}^{2} - {(0.9)}^{2} \\ \\\to \tt 900 - 0.81 \\ \\ \to \sf \green{899.19}$