1/(2x+3) = -x +7
cross-multiply
1 = (2x+3)(-x+7)
1 = -2x^2 +14x -3x +21
2x^2 -11x -20 = 0
use quadratic formula
x = {11 +/- sqrt(281)} /4
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or do you mean
1/2x + 3 = -x + 7
multiply all terms by x
1/2 + 3x = -x^2 + 7x
x^2 -4x = -1/2
x^2 -4x + 4 = 4 - 1/2
(x-2)^2 = 14/4
x-2 = +/-sqrt(14)/2
x = [4 +/- sqrt14] /2
hope this helps!
