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| Question 815705:  The abscissa of a point is two-fifths of its ordinate. Find the point if it is 5 units from (-2,2).
 Answer by TimothyLamb(4379)
      (Show Source): 
You can put this solution on YOUR website! point1 (x,y) x = (2/5)y
 y = (5/2)x
 point2 (-2,2)
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 distance between two points:
 d = sqrt( dx^2 + dy^2 )
 where:
 dx is the difference between the x-coordinates
 dy is the difference between the y-coordinates
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 d = sqrt( dx^2 + dy^2 )
 5 = sqrt( (x + 2)^2 + ((5/2)x - 2)^2 )
 25 = (x + 2)^2 + ((5/2)x - 2)^2
 25 = (x + 2)(x + 2) + ((5/2)x - 2)((5/2)x - 2)
 25 = xx + 4x + 4 + (25/4)xx - 10x + 4
 25 = (4/4)xx + (25/4)xx - 6x + 8
 (29/4)xx - 6x - 17 = 0
 7.25xx - 6x - 17 = 0
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 the above quadratic equation is in standard form, with a=7.25, b=-6, and c=-17
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 to solve the quadratic equation, plug this:
 7.25 -6 -17
 into this: https://sooeet.com/math/quadratic-equation-solver.php
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 the roots of the quadratic are:
 x = 2
 x = -1.17241379
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 Answer:
 both roots are valid values of x for point1
 (i.e. both roots answer the question as to what is the value of x for point1.)
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 point1: (2, 5)
 or
 point1: (-1.17241379, -2.9310343)
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 Solve and graph linear equations:
 https://sooeet.com/math/linear-equation-solver.php
 ---
 Solve quadratic equations, quadratic formula:
 https://sooeet.com/math/quadratic-formula-solver.php
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 Convert fractions, decimals, and percents:
 https://sooeet.com/math/fraction-decimal-percent.php
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 Calculate and graph the linear regression of any data set:
 https://sooeet.com/math/linear-regression.php
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