SOLUTION: Solve. sq.root(x^2

SOLUTION: Solve. sq.root(x^2 - 9) = 4

Question 614338: Solve.
sq.root(x^2 - 9) = 4
Answer by bucky(2189) (Show Source): You can put this solution on YOUR website!
Given to solve:
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Square both sides to get:
.

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add 9 to both sides to get rid of the -9 on the left side:
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Take the square root of both sides to get the two answers:
.
and
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You can check these two answers by returning to the original equation of:
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and first substituting +5 for x to get:
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Square the 5 and this equation becomes:
.

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Do the subtraction on the left side to get:
.

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4 is the square root of 16, so this equation reduces to:
.

.
And since this is true, we know that if x = +5, the equation works and therefore +5 is a solution.
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Next, return to the original equation of:
.

.
and this time substitute -5 for x to get:
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Square the -5 to again get +25 and this equation becomes:
.

.
Just like last time do the subtraction on the left side to get:
.

.
Again, 4 is the square root of 16, so this equation reduces to:
.

.
And since this is true, we know that if x = -5, the equation works and therefore -5 is also a solution.
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Hope this helps you to understand the problem a little more and you can see how to solve and check a problem such as this one.
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