Solve the Inequality
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((5)/(x-1)) - ((2x)/(x+1)) < 1

( 5(x+1)-2x(x-1) ) / (x^2 - 1) < 1

( 5x + 5 -2x^2 + 2x ) / (x^2 - 1) < 1

( -2x^2 + 7x  + 5 ) / (x^2 - 1) < 1

-2x^2 + 7x + 5 = 0

x = (-7 +- sqrt(7^2 - 4(-2)(5)) / 2(-2)

x = (-7 +- sqrt(49 + 40)) / -4

x = (7 +- sqrt(89)) / 4

x = (7-sqrt(89))/4, (7+sqrt(89))/4

x = about -0.6805, 4.1085

x^2 - 1 = 0

x = -1, 1

We have four places where things can change:  x = -1, -0.6805, 1, 4.1085

Let's test some values:  x = -10, -0.7, 0, 2, 5

f(x) = ((5)/(x-1)) - ((2x)/(x+1))

f(-10) = 5/-11 - (-20/-9) = -5/11 - 20/9 = negative = less than 1

f(-0.7) = 5/-1.7 - (-1.4/0.3) = -5/1.7 + 1.4/0.3 = about 1.7255 = greater than 1

f(0) = 5/-1 - 0 = -5 = less than 1

f(2) = 5/1 - 4/3 = 15/3 - 4/3 = 11/3 = greater than 1

f(5) = 5/4 - 10/6 = 15/12 - 20/12 = -5/12 = less than 1

So we don't want the regions including x = -0.7 and 2, and we do want the regions including x = -10, 0, and 5.

Answer: (x can be any of these)

x < -1

(7-sqrt(89))/4 < x < 1

(7+sqrt(89))/4 < x
by Level 13 User (103k points)

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