Question

(4x-3y-7z)^2 tell this ans​

Answer 1

step-by-step explanation:

(4x - 3y - 7z)²

∵ (a - b - c )² = a² + b² + c² - 2ab +2bc - 2cb

= (4x²) + (-3y²) + (-7z²) -2×4x×3y + 2×3y×7z - 2×7z×4x

= 16x² + 9y² + 49z² - 24xy + 42yz - 56xz

Answer 2

Step-by-step explanation:

→$\sf {(4x - 3y - 7z)}^{2}$

$\sf {4x}^{2} + {( - 3y)}^{2} + {( - 7z)}^{2} + 2(4x)( - 3y) + 2( - 3y)( - 7z) + 2( - 7z)(4x)$

$\sf {16x}^{2} + {9y}^{2} + {49z}^{2} + 24xy + 42yz - 36zx$

Procedure :-

→ This question is from Algebraic identites, and this question is from the 5th identity of the algebraic identities.

→ First we will square the 4x , -3y and -7z. And then we will multiply the numbers in the brackets and then we will multiply it with the 2 which is outside the bracket.

→ We will put negative sign in the final answer because (+)(-) = - and (+)(+) = +, but we will write 24xy because 2(-3y)(-7z) here, (+)(+) = +.

Other Identities :-

→$\sf {(x + y)}^{2} = {x}^{2} + 2xy + {y}^{2}$

→$\sf {(x - y)}^{2} = {x}^{2} - 2xy + {y}^{2}$

→$\sf (x + y)(x - y) = {x}^{2} - {y}^{2}$

→$\sf{(x + a})(x + b) = {x}^{2} + (a + b)x + (a)(b)$

______________________________________