Question
Factor the expression
4x3(x2−5x−9)
Evaluate
4x5−20x4−36x3
Rewrite the expression
4x3×x2−4x3×5x−4x3×9
Solution
4x3(x2−5x−9)
Show Solution

Find the roots
x1=25−61,x2=0,x3=25+61
Alternative Form
x1≈−1.405125,x2=0,x3≈6.405125
Evaluate
4x5−20x4−36x3
To find the roots of the expression,set the expression equal to 0
4x5−20x4−36x3=0
Factor the expression
4x3(x2−5x−9)=0
Divide both sides
x3(x2−5x−9)=0
Separate the equation into 2 possible cases
x3=0x2−5x−9=0
The only way a power can be 0 is when the base equals 0
x=0x2−5x−9=0
Solve the equation
More Steps

Evaluate
x2−5x−9=0
Substitute a=1,b=−5 and c=−9 into the quadratic formula x=2a−b±b2−4ac
x=25±(−5)2−4(−9)
Simplify the expression
More Steps

Evaluate
(−5)2−4(−9)
Multiply the numbers
(−5)2−(−36)
Rewrite the expression
52−(−36)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
52+36
Evaluate the power
25+36
Add the numbers
61
x=25±61
Separate the equation into 2 possible cases
x=25+61x=25−61
x=0x=25+61x=25−61
Solution
x1=25−61,x2=0,x3=25+61
Alternative Form
x1≈−1.405125,x2=0,x3≈6.405125
Show Solution
