Question
Factor the expression
3x(3x2−5)(3x2+5)
Evaluate
27x5−75x
Factor out 3x from the expression
3x(9x4−25)
Solution
More Steps

Evaluate
9x4−25
Rewrite the expression in exponential form
(3x2)2−52
Use a2−b2=(a−b)(a+b) to factor the expression
(3x2−5)(3x2+5)
3x(3x2−5)(3x2+5)
Show Solution

Find the roots
x1=−315,x2=0,x3=315
Alternative Form
x1≈−1.290994,x2=0,x3≈1.290994
Evaluate
27x5−75x
To find the roots of the expression,set the expression equal to 0
27x5−75x=0
Factor the expression
3x(9x4−25)=0
Divide both sides
x(9x4−25)=0
Separate the equation into 2 possible cases
x=09x4−25=0
Solve the equation
More Steps

Evaluate
9x4−25=0
Move the constant to the right-hand side and change its sign
9x4=0+25
Removing 0 doesn't change the value,so remove it from the expression
9x4=25
Divide both sides
99x4=925
Divide the numbers
x4=925
Take the root of both sides of the equation and remember to use both positive and negative roots
x=±4925
Simplify the expression
More Steps

Evaluate
4925
To take a root of a fraction,take the root of the numerator and denominator separately
49425
Simplify the radical expression
495
Simplify the radical expression
35
Multiply by the Conjugate
3×35×3
Multiply the numbers
3×315
When a square root of an expression is multiplied by itself,the result is that expression
315
x=±315
Separate the equation into 2 possible cases
x=315x=−315
x=0x=315x=−315
Solution
x1=−315,x2=0,x3=315
Alternative Form
x1≈−1.290994,x2=0,x3≈1.290994
Show Solution
