Question

Show that the numbers below are rational and write each as a fraction:

Answer 1

Answer:

a) The number is:

0.73652913

There are 8 digits after the decimal point, then we need to multiply and divide by: 100,000,000 (8 zeros at the right of the 1)

0.73652913 =  0.73652913*(100,000,000)/(100,000,000) = 73,652,913/100,000,000

So we wrote this as a fraction of two integers.

b) The number is:

0.746746...

Where the periodic part is 746.

the periodic part has 3 digits, then we can do:

0.746746...*1000 = 746.746746....

Now we can subtract the number itself to get:

746.746746... - 0.746746... = 746

And what we did is:

N*1000 - N = N*999

Then to transform the number into a quotient of integers, we can multiply and divide by 999.

0.746746... = 0.746746...*(999)/(999) = 746/999

That is a quotient of two integers, so 0.746746... is a rational number.