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प्रश्न
Using identities, evaluate 78 × 82
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उत्तर
8 × 82 = (80 − 2) (80 + 2)
= (80)2 − (2)2 [(a + b) (a − b) = a2 − b2]
= 6400 − 4 = 6396
संबंधित प्रश्न
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Take suitable number of cards given in the adjoining diagram [G(x × x) representing x2, R(x × 1) representing x and Y(1 × 1) representing 1] to factorise the following expressions, by arranging the cards in the form of rectangles:
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Factorise 2x2 + 6x + 4 by using the figure.
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Calculate the area of figure.
