Question

expand using identity. a.(20-3)² b. 39²-11²​

Answer 1

Answer:

a. 289

b. 1400

Step-by-step explanation:

a. Given,

$(20 - 3)^{2}$

we have to find the value.

$(20 - 3)^{2} = 17^{2} = 289$

b. Given,

$39^{2} - 11^{2}$

we have to find teh value of above.

$39^{2} - 11^{2} = (39 + 11)(39 - 11) = 50 \times 28 = 1400$

Answer 2

Step-by-step explanation:

a) (20-3)²

{ (20)² +(3)² -(2×20×3) } (a+b)² =a²+b²+2ab

400 + 9 - 120

409-120

289

b) 39²-11²

(39+11) (39-11) {a²-b²= (a+b)(a-b)

50 × 28

1400

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