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Nyla
07-09-2013, 02:33 PM
SAT math proportions - scale

I need help please to the following sat math question:

"On a map that is drawn to scale, two cities that are m miles apart while are 5 inches apart on the map. If two other cities are m+4 miles apart, how many inches apart would they be on the same map?"

Thanks!!:):)

miranda
07-09-2013, 02:44 PM
SAT mathematics proportions

A proportion is an equation which states that two ratios are equal.

When the terms of a proportion are cross multiplied, the cross products are equal.

Cross multiplication is the multiplication of the numerator of the first ratio by the denominator of the second ratio and the multiplication of the denominator of the first ratio by the numerator of the second ratio.

The corresponding measure are proportional and let x be the required distance

So, \frac{m}{5}=\frac{m+4}{x}

mx=5(m+4)

x=\frac{5(m+4)}{m}

Hope these help!!:)

Nyla
07-09-2013, 02:45 PM
Thanks Miranda!!;)