Identify Conjugate of Denominator: Identify the conjugate of the denominator.The conjugate of a number in the form of a+b is a−b. Therefore, the conjugate of 4+5 is 4−5.
Multiply by Conjugate: Multiply the numerator and the denominator by the conjugate of the denominator.To rationalize the denominator, we multiply the numerator and the denominator by the conjugate of the denominator.4+54⋅4−54−5
Distribute Numerator: Distribute the numerator.Multiply 4 by the conjugate of the denominator.4×(4−5)=16−45
Expand Denominator: Expand the denominator using the difference of squares formula.(4+5)×(4−5)=42−(5)2=16−5=11
Write Simplified Expression: Write the simplified expression.Place the simplified numerator over the simplified denominator.(16−45)/11This is the expression with the denominator rationalized.
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