Question
Simplify the expression
21x3−6x4−9x2
Evaluate
(2x−1)×3x2(3−x)
Multiply the first two terms
3x2(2x−1)(3−x)
Multiply the terms
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Evaluate
3x2(2x−1)
Apply the distributive property
3x2×2x−3x2×1
Multiply the terms
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Evaluate
3x2×2x
Multiply the numbers
6x2×x
Multiply the terms
6x3
6x3−3x2×1
Any expression multiplied by 1 remains the same
6x3−3x2
(6x3−3x2)(3−x)
Apply the distributive property
6x3×3−6x3×x−3x2×3−(−3x2×x)
Multiply the numbers
18x3−6x3×x−3x2×3−(−3x2×x)
Multiply the terms
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Evaluate
x3×x
Use the product rule an×am=an+m to simplify the expression
x3+1
Add the numbers
x4
18x3−6x4−3x2×3−(−3x2×x)
Multiply the numbers
18x3−6x4−9x2−(−3x2×x)
Multiply the terms
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Evaluate
x2×x
Use the product rule an×am=an+m to simplify the expression
x2+1
Add the numbers
x3
18x3−6x4−9x2−(−3x3)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
18x3−6x4−9x2+3x3
Solution
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Evaluate
18x3+3x3
Collect like terms by calculating the sum or difference of their coefficients
(18+3)x3
Add the numbers
21x3
21x3−6x4−9x2
Show Solution

Find the roots
x1=0,x2=21,x3=3
Alternative Form
x1=0,x2=0.5,x3=3
Evaluate
(2x−1)(3x2)(3−x)
To find the roots of the expression,set the expression equal to 0
(2x−1)(3x2)(3−x)=0
Multiply the terms
(2x−1)×3x2(3−x)=0
Multiply the first two terms
3x2(2x−1)(3−x)=0
Elimination the left coefficient
x2(2x−1)(3−x)=0
Separate the equation into 3 possible cases
x2=02x−1=03−x=0
The only way a power can be 0 is when the base equals 0
x=02x−1=03−x=0
Solve the equation
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Evaluate
2x−1=0
Move the constant to the right-hand side and change its sign
2x=0+1
Removing 0 doesn't change the value,so remove it from the expression
2x=1
Divide both sides
22x=21
Divide the numbers
x=21
x=0x=213−x=0
Solve the equation
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Evaluate
3−x=0
Move the constant to the right-hand side and change its sign
−x=0−3
Removing 0 doesn't change the value,so remove it from the expression
−x=−3
Change the signs on both sides of the equation
x=3
x=0x=21x=3
Solution
x1=0,x2=21,x3=3
Alternative Form
x1=0,x2=0.5,x3=3
Show Solution
