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4 votes
Multiplying a number by 4/5 then dividing by 2/5 is the same as multiplying by what number?

User Jarussi
by
7.4k points

2 Answers

4 votes
number * 4/5 * reciprocal of 2/5
number * 4/5 * 5/2 = number * 20/10 = number * 2

2
User Sebastien Lachance
by
6.9k points
6 votes
So say the number equals x.

Therefore, it would be:

x * 4/5 / 2/5

Division is basically multiplying by the second number flipped, like so:

x * 4/5 * 5/2

Then you could just multiply, saying

x * 20/10

or x * 2

So it's the same as multiplying by 2.
User Jonathan Olson
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7.7k points