x - (1.19/x) = 0.30
multiply both sides by x
x^2 - 1.19 = 0.30x
subtract 0.30x from both sides
x^2 - 0.30x - 1.19 = 0
quadratic formula
x = (0.3 +- sqrt (0.3^2 - 4(1)(-1.19) ) ) /2(1)
x = (0.3 +- sqrt(0.09 + 4.76) )/2
x = (0.3 +- sqrt(4.85) )/2
x = (0.3 +- 2.20)/2
it's money and we can't have negative money, so:
x = (0.3 + 2.2)/2
x = 2.5/2
x = 1.25