Question 119943This question is from textbook
: How would you solve this equation?
z=8*square root of z +240
Any help is appreciated thanks alot! This question is from textbook
You can put this solution on YOUR website! Assume you mean:
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z =
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We want to get the radical on one side by itself; subtract 240 from both sides
z - 240 =
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Now squaring both sides get rid of the radical,
(z-240)^2 = 64(z)
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FOIL the left side:
z^2 - 480z + 57600 = 64z
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Arrange as a quadratic equation, subtract 64z from both sides:
z^2 - 480z - 64z + 57600 = 0
z^2 - 544z + 57600 = 0
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This looks like a sure candidate for the quadratic formula, but actually it will factor:
(z - 400)(z - 144) = 0
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z = 400 or z = 144
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Try both of these solution in the original equation
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z=400 =
8(20) + 240 = 400; a good solution
and
z=144
8(12) + 240 = 336 does not = 144 so that is not a solution
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This is often the case when dealing with square roots, always check all your solution in the original equation.
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Did this make sense to you, Any questions?
