Find the Roots/Zeros Using the Rational Roots Test f(x)=x^4+4x^3-14x^2-36x+45

Math
If a polynomial function has integer coefficients, then every rational zero will have the form where is a factor of the constant and is a factor of the leading coefficient.
Find every combination of . These are the possible roots of the polynomial function.
Substitute the possible roots one by one into the polynomial to find the actual roots. Simplify to check if the value is , which means it is a root.
Simplify the expression. In this case, the expression is equal to so is a root of the polynomial.
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Simplify each term.
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One to any power is one.
One to any power is one.
Multiply by .
One to any power is one.
Multiply by .
Multiply by .
Simplify by adding and subtracting.
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Add and .
Subtract from .
Subtract from .
Add and .
Since is a known root, divide the polynomial by to find the quotient polynomial. This polynomial can then be used to find the remaining roots.
Next, find the roots of the remaining polynomial. The order of the polynomial has been reduced by .
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Place the numbers representing the divisor and the dividend into a division-like configuration.
  
The first number in the dividend is put into the first position of the result area (below the horizontal line).
  
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
  
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
  
Multiply the newest entry in the result by the divisor and place the result of under the next term in the dividend .
 
Add the product of the multiplication and the number from the dividend and put the result in the next position on the result line.
 
All numbers except the last become the coefficients of the quotient polynomial. The last value in the result line is the remainder.
Simplify the quotient polynomial.
Factor out the greatest common factor from each group.
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Group the first two terms and the last two terms.
Factor out the greatest common factor (GCF) from each group.
Factor the polynomial by factoring out the greatest common factor, .
Rewrite as .
Factor.
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Since both terms are perfect squares, factor using the difference of squares formula, where and .
Remove unnecessary parentheses.
Factor the left side of the equation.
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Regroup terms.
Factor out of .
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Factor out of .
Factor out of .
Factor out of .
Rewrite as .
Factor.
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Since both terms are perfect squares, factor using the difference of squares formula, where and .
Remove unnecessary parentheses.
Rewrite as .
Let . Substitute for all occurrences of .
Factor using the AC method.
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Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Write the factored form using these integers.
Replace all occurrences of with .
Rewrite as .
Since both terms are perfect squares, factor using the difference of squares formula, where and .
Factor out of .
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Factor out of .
Factor out of .
Let . Substitute for all occurrences of .
Factor using the AC method.
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Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Write the factored form using these integers.
Factor.
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Replace all occurrences of with .
Remove unnecessary parentheses.
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Set the first factor equal to and solve.
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Set the first factor equal to .
Subtract from both sides of the equation.
Set the next factor equal to and solve.
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Set the next factor equal to .
Add to both sides of the equation.
Set the next factor equal to and solve.
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Set the next factor equal to .
Add to both sides of the equation.
Set the next factor equal to and solve.
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Set the next factor equal to .
Subtract from both sides of the equation.
The final solution is all the values that make true.
Find the Roots/Zeros Using the Rational Roots Test f(x)=x^4+4x^3-14x^2-36x+45
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