How do you solve x/900 = 3.5/15?

Mar 29, 2018

$x = 210$

Explanation:

$\frac{x}{900} = \frac{3.5}{15}$

You would cross multiply and get;

$15 \times x = 900 \times 3.5$

$15 x = 3150$

Then divide by $15$ on both sides;

$\frac{15 x}{15} = \frac{3150}{15}$

$\frac{\cancel{15} x}{\cancel{15}} = \frac{3150}{15}$

$x = \frac{3150}{15}$

$x = 210$

Mar 29, 2018

$x = 210$

Explanation:

$\frac{x}{900} = \frac{3.5}{15}$ (Multiply both sides by 900 to isolate the variable)

$x = \frac{3.5}{15} \cdot 900$ (15 is a factor of 900, so you can reduce 900 to 60 and 15 to 1)

$x = 3.5 \cdot 60$

$x = 210$

Check the answer by plugging it into the original equation:

$\frac{210}{900} = \frac{3.5}{15}$

$0.23 = 0.23$