Question
Factor the expression
(2x−9)(4x2+18x+81)
Evaluate
8x3−729
Rewrite the expression in exponential form
(2x)3−93
Use a3−b3=(a−b)(a2+ab+b2) to factor the expression
(2x−9)((2x)2+2x×9+92)
Evaluate
More Steps

Evaluate
(2x)2
To raise a product to a power,raise each factor to that power
22x2
Evaluate the power
4x2
(2x−9)(4x2+2x×9+92)
Evaluate
(2x−9)(4x2+18x+92)
Solution
(2x−9)(4x2+18x+81)
Show Solution

Find the roots
x=29
Alternative Form
x=4.5
Evaluate
8x3−729
To find the roots of the expression,set the expression equal to 0
8x3−729=0
Move the constant to the right-hand side and change its sign
8x3=0+729
Removing 0 doesn't change the value,so remove it from the expression
8x3=729
Divide both sides
88x3=8729
Divide the numbers
x3=8729
Take the 3-th root on both sides of the equation
3x3=38729
Calculate
x=38729
Solution
More Steps

Evaluate
38729
To take a root of a fraction,take the root of the numerator and denominator separately
383729
Simplify the radical expression
More Steps

Evaluate
3729
Write the number in exponential form with the base of 9
393
Reduce the index of the radical and exponent with 3
9
389
Simplify the radical expression
More Steps

Evaluate
38
Write the number in exponential form with the base of 2
323
Reduce the index of the radical and exponent with 3
2
29
x=29
Alternative Form
x=4.5
Show Solution
