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# Need help ASAP!

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The length of the segment between the points $$(2a, a-4)$$ and $$(4, -1)$$ is $$2\sqrt{10}$$ units. What is the product of all possible values for $$a$$?

Apr 2, 2019

#1
+18754
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Distance between the two points is given by the distance formula

(2a-4)^2  +  ((a-4)--1)^2

4a^2 -16a+16    +  a^2-6a +9  = (2 sqrt10)^2

5 a^2 -22a + 25 = 40

5a^2-22a - 15 = 0

a = 5 or -3/5        (by Quadratic Formula)

5 * -3/5 =    -3

Apr 2, 2019
#2
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what do you mean by Quadratic Formula

Apr 2, 2019
#3
+4299
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$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$, so you can find the values !

Apr 2, 2019
#4
+18754
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Agree with Tertre....

5a^2-22a - 15 = 0

Use Quadratic Formula   (as Tertre posted)   a = 5   b = -22   c = -15     to find the possible values of 'a' in the equation

ElectricPavlov  Apr 2, 2019