Question

solve for x in the proportion
x 1
---- = ----
x+12 x-1

answers are not exact. they are rounded.

a: x=-6.02 and x=5.02
b: x=-3.46 and x=3.46
c: x=-3.14 and x=4.14
d: x=-2.61 and x=4.61

Answer 1

solve this equation for x: \[x(x-1) - (x+12) = 0\]
which reduces to a quadratic:
\[x^2 - 2x - 12 = 0\]
which we use the formula to solve:
\[x=\frac{2 \pm \sqrt{52}}{2}\]
\[x=\frac{2 \pm 2\sqrt{13}}{2}\]
\[x=1 \pm \sqrt{13} = 1 \pm 3.6055\]
\[ x = 4.61, x = -2.61\]

Answer 2

so answer is d

Answer 3

how did you get x(x-1)-(x+12) ?

Answer 4

is it like a certain equation ? because to solve for proportions and ratios i usually cross multiply

Answer 5

Take your starting equation:
\[\frac{x}{x+12} = \frac{1}{x-1}\]
multiply both sides by (x-1) to give
\[\frac{x(x-1)}{x+12} = 1\]
then multiply both sides by (x+12)
\[x(x-1) = x+12\]
so we have removed the fractions. Now just take (x+12) to the other side:
\[x(x-1) - (x+12) = 0\]

Answer 6

oh okay ! i see . thank you(: