solve x^3-81x by factoring?

Yeah, he got it.

Take out a factor of x.

x(x^2-81)

In the brackets you have the difference of two squares.

x^2-y^2 = (x+y)(x-Y)

Since:

x^2 - 81 = (x)^2 - (9)^2

x = x
y = 9

x(x+9)(x-9)

this factors to x(x^2-81) which then you can factor further to: x(x+9)(x-9)

Factoring: 81x^6+24x^3y^3 3x³(27x³ + 8y³) Rectangle: Area of rectangle = L*W substituting the given expressions for A and L: x³+12x²+47x+60 = (x+5)W solving for W: W = (x³+12x²+47x+60)/(x+5) reducing the fraction: W = x²+7x+12

x ( x ² - 81 )
x ( x - 9 ) ( x + 9 )

x^3 - 81x
= x(x^2 - 81)
= x(x - 9)(x + 9)

:)

x^3-81x
=x(x-81)
=x(x+9)(x-9) answer//

x(x^2-81)=x(x+9)(x-9)

Well first off, the common factor of x^3 - 81x is x so it's
x(x^2 - 81)
And we can factorize x^2 - 81 into
x(x + 9)(x - 9)

x(x^2-81)=x(x-9)(x+9)

a^2 - b^2 = (a - b)(a + b)

x^3 - 81x
= x(x^2 - 81)
= x(x^2 - 9^2)
= x(x + 9)(x - 9)