Find the cube of the following binomial expression : 1/x + y/3

Cube of Binomial Expression Find the Cube of the Following Binomial Expression \[ \frac{1}{x}+\frac{y}{3} \] Solution: Using identity: \[ (a+b)^3 = a^3+b^3+3ab(a+b) \] \[ \left(\frac{1}{x}+\frac{y}{3}\right)^3 \] \[ = \left(\frac{1}{x}\right)^3 + \left(\frac{y}{3}\right)^3 + 3\left(\frac{1}{x}\right)\left(\frac{y}{3}\right) \left(\frac{1}{x}+\frac{y}{3}\right) \] \[ = \frac{1}{x^3} + \frac{y^3}{27} + \frac{y}{x} \left(\frac{1}{x}+\frac{y}{3}\right) \] \[ = \frac{1}{x^3} + \frac{y^3}{27} + \frac{y}{x^2} + \frac{y^2}{3x} \] Next […]

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Simplify the following expression : (x + y – 2z)^2 – x^2 – y^2 – 3z^2 + 4xy

Simplify Expression Using Identity Simplify the Following Expression \[ (x+y-2z)^2-x^2-y^2-3z^2+4xy \] Solution: Using identity: \[ (a+b-c)^2 = a^2+b^2+c^2+2ab-2bc-2ca \] \[ (x+y-2z)^2 = x^2+y^2+(2z)^2+2xy-2(y)(2z)-2(x)(2z) \] \[ = x^2+y^2+4z^2+2xy-4yz-4xz \] \[ (x+y-2z)^2-x^2-y^2-3z^2+4xy \] \[ = x^2+y^2+4z^2+2xy-4yz-4xz -x^2-y^2-3z^2+4xy \] \[ = z^2+6xy-4yz-4xz \] Next Question / Full Exercise

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Simplify the following expression : (x + y + z)^2 + (x + y/2 + z/3)^2 – (x/2 + y/3 + z/4)^2

Simplify Expression Using Identity Simplify the Following Expression \[ (x+y+z)^2+\left(x+\frac{y}{2}+\frac{z}{3}\right)^2-\left(\frac{x}{2}+\frac{y}{3}+\frac{z}{4}\right)^2 \] Solution: Using identity: \[ (a+b+c)^2=a^2+b^2+c^2+2ab+2bc+2ca \] \[ (x+y+z)^2 = x^2+y^2+z^2+2xy+2yz+2zx \] \[ \left(x+\frac{y}{2}+\frac{z}{3}\right)^2 = x^2+\frac{y^2}{4}+\frac{z^2}{9} +xy+\frac{yz}{3}+\frac{2xz}{3} \] \[ \left(\frac{x}{2}+\frac{y}{3}+\frac{z}{4}\right)^2 = \frac{x^2}{4}+\frac{y^2}{9}+\frac{z^2}{16} +\frac{xy}{3}+\frac{yz}{6}+\frac{xz}{4} \] \[ (x+y+z)^2+\left(x+\frac{y}{2}+\frac{z}{3}\right)^2-\left(\frac{x}{2}+\frac{y}{3}+\frac{z}{4}\right)^2 \] \[ = \frac{7x^2}{4} +\frac{41y^2}{36} +\frac{127z^2}{144} +\frac{8xy}{3} +\frac{13yz}{6} +\frac{29xz}{12} \] Next Question / Full Exercise

Simplify the following expression : (x + y + z)^2 + (x + y/2 + z/3)^2 – (x/2 + y/3 + z/4)^2 Read More »

Simplify : (a + b + c)^2 + (a – b + c)^2 + (a + b – c)^2

Simplify Using Algebraic Identity Simplify \[ (a+b+c)^2 + (a-b+c)^2 + (a+b-c)^2 \] Solution: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (a-b+c)^2 = a^2+b^2+c^2-2ab-2bc+2ca \] \[ (a+b-c)^2 = a^2+b^2+c^2+2ab-2bc-2ca \] \[ (a+b+c)^2 + (a-b+c)^2 + (a+b-c)^2 \] \[ = 3a^2+3b^2+3c^2+2ab-2bc+2ca \] Next Question / Full Exercise

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Find the value of 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx when x = 4, y = 3 and z = 2.

Find the Value Using Identity Find the Value \[ 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx \] Given: \[ x=4,\quad y=3,\quad z=2 \] Solution: Using identity: \[ (a+b-c)^2 = a^2+b^2+c^2+2ab-2bc-2ca \] \[ 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx \] \[ = (2x)^2 + y^2 + (5z)^2

Find the value of 4x^2 + y^2 + 25z^2 + 4xy – 10yz – 20zx when x = 4, y = 3 and z = 2. Read More »

If a + b + c = 9 and ab + bc + ca = 23, find the value of a^2 + b^2 + c^2.

Find the Value Using Identity Find the Value \[ a+b+c=9 \] \[ ab+bc+ca=23 \] Find: \[ a^2+b^2+c^2 \] Solution: Using identity: \[ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca \] \[ (9)^2 = a^2+b^2+c^2+2(23) \] \[ 81 = a^2+b^2+c^2+46 \] \[ a^2+b^2+c^2 = 81-46 \] \[ =35 \] Next Question / Full Exercise

If a + b + c = 9 and ab + bc + ca = 23, find the value of a^2 + b^2 + c^2. Read More »