What is #0.75757575...# as a fraction?

3 Answers
Sep 14, 2017

#0.757575... = 25/33#

Explanation:

Note that #1/99 = 0.010101...#

So:

#0.757575... = 75*0.010101... = 75*1/99 = 75/99 = (25*color(red)(cancel(color(black)(3))))/(33*color(red)(cancel(color(black)(3)))) = 25/33#

Sep 16, 2017

#.7575757575...=25/33#

Explanation:

Another approach

#x=0.75757575........#

#100x=75 .color(red)(75757575...)#

# x = " " 0. color(red)(75757575....)#

subtract the two and the recurring decimals cancel, shown in red

#=>99x=75#

#:.x=75/99#

cancel with #3#

#=(cancel(3)xx25)/(cancel(3)xx33)#

#.7575757575...=25/33#

Sep 16, 2017

#0.75 = 75/99 = 25/33#

Explanation:

The complete explanation has been given elsewhere, but here is a nifty short cut.

If ALL the digits recur, write a fraction as:

#("the digits which recur")/("a 9 for each digit")#

#0.75757575.... = 0.dot7dot5 = 0.bar(75)#

Fraction = #75/99#

This simplies by #3# to give #25/33#

You can confirm with a calculator that #25/33 = 0.757575...#