2. Write the mixed repeating (recurring) decimal number as a proper fraction.
0.86607 can be written as a proper fraction.
- The numerator is smaller than the denominator.
Set up the first equation.
- Let y equal the decimal number:
y = 0.86607
Set up the second equation.
- Number of decimal places repeating: 1
Multiply both sides of the first equation by 101 = 10
y = 0.86607
10 × y = 10 × 0.86607
10 × y = 8.6607
Get the same number of decimal places as for y:
10 × y = 8.66077
Note: 8.66077 = 8.6607
Subtract the first equation from the second one.
- Having the same number of decimal places ...
- The repeating pattern drops off by subtracting the two equations.
10 × y - y = 8.66077 - 0.86607 ⇒
(10 - 1) × y = 8.66077 - 0.86607 ⇒
We now have a new equation:
9 × y = 7.7947
Solve for y in the new equation.
9 × y = 7.7947 ⇒
y = 7.7947/9
Let the result written as a fraction.
Now we can write the number as a fraction.
According to our first equation:
y = 0.86607
According to our calculations:
y = 7.7947/9
⇒ 0.86607 = 7.7947/9
Get rid of the decimal places in the fraction above.
- Multiply the top and the bottom number by 10,000.
- 1 followed by as many 0-s as the number of digits after the decimal point.
0.86607 = (7.7947 × 10,000)/(9 × 10,000)
0.86607 = 77,947/90,000
3. Reduce (simplify) the fraction above:
77,947/90,000
to the lowest terms, to its simplest equivalent form, irreducible.
To reduce a fraction to the lowest terms divide the numerator and denominator by their greatest (highest) common factor (divisor), GCF.
Factor the numerator and denominator (prime factorization).
77,947 = 23 × 3,389
90,000 = 24 × 32 × 54
Calculate the greatest (highest) common factor (divisor), GCF.
Multiply all the common prime factors by the lowest exponents.
But, the numerator and the denominator have no common factors.
GCF (23 × 3,389; 24 × 32 × 54) = 1
The numerator and the denominator are coprime numbers (no common prime factors, GCF = 1). So, the fraction cannot be reduced (simplified): irreducible fraction.