# Math Help - solve for one variable - fractions

1. ## solve for one variable - fractions

I am trying to understand the basics of how to do this.

$x/16 = 4/x$

Can you assist in getting me on the right track?

The answer is + or - 8 and it seems clear to me that one side should say x^2 and the other 64, I am just not positive of which way is the correct way to get the answer.

Thank you.

2. $\frac{x}{16} = \frac{4}{x}$

Cross multiplying

$\frac{x}{16}\times x = \frac{4}{x}\times x$

$\frac{x^2}{16} = 4$

$\frac{x^2}{16}\times 16 = 4 \times 16$

$x^2 = 64$

$x = \sqrt{64}$

$x = \pm 8$