Find the following product : (x/2 + 2y) (x^2/4 – xy + 4y^2)

Find the Product (x/2 + 2y)(x²/4 − xy + 4y²) Find the Product: \[ \left(\frac{x}{2} + 2y\right)\left(\frac{x^2}{4} – xy + 4y^2\right) \] Solution: Using identity: \[ (a+b)(a^2-ab+b^2)=a^3+b^3 \] Here, \[ a=\frac{x}{2},\qquad b=2y \] \[ \left(\frac{x}{2} + 2y\right)\left(\frac{x^2}{4} – xy + 4y^2\right) \] \[ = \left(\frac{x}{2} + 2y\right) \left[\left(\frac{x}{2}\right)^2 – \left(\frac{x}{2}\right)(2y) + (2y)^2\right] \] \[ = […]

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Find the following product : (7p^4 + q) (49p^8 – 7p^4q + q^2)

Find the Product (7p⁴ + q)(49p⁸ − 7p⁴q + q²) Find the Product: \[ (7p^4 + q)(49p^8 – 7p^4q + q^2) \] Solution: Using identity: \[ (a+b)(a^2-ab+b^2)=a^3+b^3 \] Here, \[ a=7p^4,\qquad b=q \] \[ (7p^4 + q)(49p^8 – 7p^4q + q^2) \] \[ = (7p^4 + q)\left[(7p^4)^2 – (7p^4)(q) + q^2\right] \] \[ = (7p^4)^3

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If x^4 + 1/x^4 = 119, find the value of x^3 – 1/x^3

Find the Value Using Identity Find the Value \[ x^4+\frac{1}{x^4}=119 \] Find: \[ x^3-\frac{1}{x^3} \] Solution: Using identity: \[ \left(x^2+\frac{1}{x^2}\right)^2 = x^4+\frac{1}{x^4}+2 \] \[ \left(x^2+\frac{1}{x^2}\right)^2 = 119+2 \] \[ \left(x^2+\frac{1}{x^2}\right)^2 = 121 \] \[ x^2+\frac{1}{x^2} = 11 \] Now, \[ \left(x-\frac{1}{x}\right)^2 = x^2+\frac{1}{x^2}-2 \] \[ \left(x-\frac{1}{x}\right)^2 = 11-2 \] \[ \left(x-\frac{1}{x}\right)^2 = 9 \] \[

If x^4 + 1/x^4 = 119, find the value of x^3 – 1/x^3 Read More »

If x^4 + 1/x^4 = 194, find x^3 + 1/x^3 , x^2 + 1/x^2 and x + 1/x

Find Values Using Identity Find the Following Values \[ x^4+\frac{1}{x^4}=194 \] Find: \[ x^3+\frac{1}{x^3},\quad x^2+\frac{1}{x^2},\quad x+\frac{1}{x} \] Solution: Using identity: \[ \left(x^2+\frac{1}{x^2}\right)^2 = x^4+\frac{1}{x^4}+2 \] \[ \left(x^2+\frac{1}{x^2}\right)^2 = 194+2 \] \[ \left(x^2+\frac{1}{x^2}\right)^2 = 196 \] \[ x^2+\frac{1}{x^2} = 14 \] Now, \[ \left(x+\frac{1}{x}\right)^2 = x^2+\frac{1}{x^2}+2 \] \[ \left(x+\frac{1}{x}\right)^2 = 14+2 \] \[ \left(x+\frac{1}{x}\right)^2 = 16

If x^4 + 1/x^4 = 194, find x^3 + 1/x^3 , x^2 + 1/x^2 and x + 1/x Read More »

Simplify the following : (2x – 5y)^3 – (2x + 5y)^3

Simplify Using Identity Simplify the Following \[ (2x-5y)^3-(2x+5y)^3 \] Solution: Let \[ a=2x-5y,\quad b=2x+5y \] Using identity: \[ a^3-b^3=(a-b)(a^2+ab+b^2) \] \[ a-b = (2x-5y)-(2x+5y) = -10y \] \[ ab = (2x-5y)(2x+5y) = 4x^2-25y^2 \] \[ a+b = 4x \] \[ a^2+ab+b^2 = (a+b)^2-3ab \] \[ = (4x)^2-3(4x^2-25y^2) \] \[ = 16x^2-12x^2+75y^2 \] \[ = 4x^2+75y^2

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Simplify the following : (x + 2/x)^3 + (x – 2/x)^3

Simplify Using Identity Simplify the Following \[ \left(x+\frac{2}{x}\right)^3 + \left(x-\frac{2}{x}\right)^3 \] Solution: Let \[ a=x+\frac{2}{x},\quad b=x-\frac{2}{x} \] Using identity: \[ a^3+b^3=(a+b)(a^2-ab+b^2) \] \[ a+b = 2x \] \[ ab = \left(x+\frac{2}{x}\right) \left(x-\frac{2}{x}\right) = x^2-\frac{4}{x^2} \] \[ a^2-ab+b^2 = (a+b)^2-3ab \] \[ = (2x)^2 -3\left(x^2-\frac{4}{x^2}\right) \] \[ = 4x^2-3x^2+\frac{12}{x^2} \] \[ = x^2+\frac{12}{x^2} \] \[ a^3+b^3

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Simplify the following : (x/2 + y/3)^3 – (x/2 – y/3)^3

Simplify Using Identity Simplify the Following \[ \left(\frac{x}{2}+\frac{y}{3}\right)^3 – \left(\frac{x}{2}-\frac{y}{3}\right)^3 \] Solution: Let \[ a=\frac{x}{2}+\frac{y}{3},\quad b=\frac{x}{2}-\frac{y}{3} \] Using identity: \[ a^3-b^3=(a-b)(a^2+ab+b^2) \] \[ a-b = \frac{2y}{3} \] \[ a+b = x \] \[ ab = \left(\frac{x}{2}+\frac{y}{3}\right) \left(\frac{x}{2}-\frac{y}{3}\right) = \frac{x^2}{4}-\frac{y^2}{9} \] \[ a^2+ab+b^2 = (a+b)^2-ab \] \[ = x^2-\left(\frac{x^2}{4}-\frac{y^2}{9}\right) \] \[ = \frac{3x^2}{4}+\frac{y^2}{9} \] \[ a^3-b^3

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