Write the fraction 2/3 as the sum of unit fraction

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  1/2 + 1/6

Step-by-step explanation:

  2/3 = 1/2 + 1/6

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The sum of unit fractions is called an Egyptian Fraction. There are several different algorithms for finding such a sum. Here, we are starting with the form ...

  2/p

where p is a small prime. Then the sum can be written as ...

  1/((p+1)/2) +1/(p(p+1)/2) = 1/(4/2) +1/(3(4/2)) = 1/2 + 1/6

A different algorithm is used when p is a composite number.

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Using the "greedy" algorithm, we can find the largest unit fraction less than 2/3 to be ...

  1/ceil(3/2) = 1/2

Then the largest unit fraction in the remainder is similarly found. The remainder is ...

  2/3 -1/2 = 1/6 . . . . already a unit fraction

So, the sum is ...

  2/3 = 1/2 + 1/6

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: