McGraw Hill Glencoe Algebra 2, 2012
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McGraw Hill Glencoe Algebra 2, 2012 View details
7. Solving Radical Equations and Inequalities
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Exercise 6 Page 432

Raise each side of the equation to the reciprocal of the rational exponent.

x=13

Practice makes perfect

Solving a equation with an expression raised to a rational exponent usually involves three main steps.

  1. Isolate the expression raised to a rational exponent on one side of the equation.
  2. Raise each side of the equation to a power equal to the reciprocal of the rational exponent.
  3. Solve the resulting equation. Remember to check your results!
Now we can analyze the given equation. (x-5)^(13)-4=-2 First, let's isolate the expression raised to a rational exponent, (x-5)^(13), on one side of the equation.
(x-5)^(13)-4=-2
(x-5)^(13)=2
In order to remove the 13 power, or cube root, we will raise each side of the equation to the power of 3.
(x-5)^(13)=2
[(x-5)^(13)]^3=2^3
â–Ľ
Solve for x
(x-5)^1=2^3
x-5=8
x=13
Next, we will check the solution by substituting 13 for x into the original equation. If the substitution produces a true statement, we know that our answer is correct. If it does not, then it is an extraneous solution.
(x-5)^(13)-4=-2
( 13-5)^(13)-4? =-2
â–Ľ
Simplify
(8)^(13)-4? =-2
(2^3)^(13)-4? =-2
2^1-4? =-2
2-4? =-2
-2=-2 âś“
Because our substitution produced a true statement, we know that our answer, x=13, is correct.