Question

$705 \times ( - 36) \times ( - 705) \times 64$
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Answer 1

$705 \times ( - 36) \times ( - 705) \times 64$

$- {(705)}^{2} \times ( - 36) \times 64$

$- (700 + 5)^{2} \times ( - 2304)$

$- (700)^{2} + {(5)}^{2} + 2 \times 700 \times 5 \times ( - 2304)$

$- (4900 + 25 + 7000) \times ( - 2304)$

$- 11925 \times ( - 2304)$

$69500$

$\rm \: \therefore \: the \: answer \: is \: 69500$

Formula used for 705 × 705 : (a+b)²