Expand: (2a - 5b - 4c)^2

Using the formula, [∵ (x \- y \- z) 2 = x 2 \+ y 2 \+ z 2 \- 2xy \+ 2yz \- 2xz] ⇒ (2a \- 5b \- 4c) 2 = (2a) 2 \+ (5b) 2 \+ (4c) 2 \- 2 (2a) (5b) \+ 2 (5b) (4c) \- 2 (4c) (2a) = 4a 2 \+ 25b 2 \+ 16c 2 \- 20ab \+ 40bc \- 16ca Hence, (2a \- 5b \- 4c) 2 = 4a 2 \+ 25b 2 \+ 16c 2 \- 20ab \+ 40bc \- 16ca.

Mathematics

Expand:
(2a - 5b - 4c)²

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Using the formula,

[∵ (x - y - z)² = x² + y² + z² - 2xy + 2yz - 2xz]

⇒ (2a - 5b - 4c)² = (2a)² + (5b)² + (4c)² - 2 $\times$ (2a) $\times$ (5b) + 2 $\times$ (5b) $\times$ (4c) - 2 $\times$ (4c) $\times$ (2a)

= 4a² + 25b² + 16c² - 20ab + 40bc - 16ca

Hence, (2a - 5b - 4c)² = 4a² + 25b² + 16c² - 20ab + 40bc - 16ca.

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Mathematics

Expand:
(2a - 5b - 4c)²

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If $3x -\dfrac{1}{3x}= 5$ , find:
(i) $9x^2 +\dfrac{1}{9x^2}$
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Mathematics

Expand:(2a - 5b - 4c)2

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If 3x−13x=53x -\dfrac{1}{3x}= 53x−3x1​=5, find:(i) 9x2+19x29x^2 +\dfrac{1}{9x^2}9x2+9x21​(ii) 81x4+181x481x^4 +\dfrac{1}{81x^4}81x4+81x41​

Expand:(3x - 4y + 5z)2

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Expand:
(2a - 5b - 4c)²

If $3x -\dfrac{1}{3x}= 5$ , find:
(i) $9x^2 +\dfrac{1}{9x^2}$
(ii) $81x^4 +\dfrac{1}{81x^4}$

Expand:
(3x - 4y + 5z)²

Expand:
(5x + 3y)³

Expand:
(6a - 7b)³