SOLUTION: the positive root of the equation X^2+15=30 lies between

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Question 622172: the positive root of the equation X^2+15=30 lies between
Answer by math-vortex(648) About Me  (Show Source):
You can put this solution on YOUR website!
Hi, there--
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x%5E2%2B15=30
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Solve for x. Subtract 15 from both sides.
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x%5E2=30-15
x%5E2=15
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Take the positive square root of both sides of the equation. If x^2 equals 15, then
x=sqrt%2815%29
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To find which integers the square root of 15 is between, we find the two square numbers closest to 15 (one less than 15 and one greater than 15.} The square numbers are 1, 4, 9, 16, ...
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15 is between 9 and 16.
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Therefore, sqrt%2815%29 is between sqrt%289%29=3 and sqrt%2816%29=4. So the positive root of x%5E2%2B15=30 lies between 3 and 4.