What is #9/15 + 3/45#?

3 Answers
Mar 4, 2018

#2/3#

Explanation:

#=> 9/15 + 3/45#

#=> (9/15 × 3/3) + 3/45#

#=> 27/45 + 3/45#

#=> (27 + 3)/45#

#=> 30/45#

#=> (15 × 2)/(15 × 3)#

#=> (cancel(15) × 2)/(cancel(15) × 3)#

#=> 2/3#

Mar 4, 2018

The answer is #2/3#.

Explanation:

#9/15+3/45#

Reduce the fraction to 3.
#=3/5+1/15#

Write all numerators above the least common denominator 15.
#=(9+1)/15#

Add the numbers.
#=10/15#

Reduce the fraction to 5.
#=2/3#

:)

Mar 4, 2018

#2/3#

Explanation:

In order to add fractions, they must have the same denominator. The easiest way to give them the same denominator is to find their Least Common Factor. This will insure that we have the lowest number possible as the denominator (making it easier to solve the problem).
To do this, list the multiples of both denominators and find the lowest multiple that is the same
15: 15, 30, #color(red)45#, 60...
45: #color(red)45#, 90, 135...

So let's change the bottom of the both fractions to 45.
#9/15 xx (3/3) rarr 27/45# (because we multiplied the bottom by 3 to get 45, we had to also multiply the top by 3).
The second fraction already has a denominator of 45, so we will leave it alone.
#27/45 + 3/45 = 30/45#

Now let's simplify it, since that is a rather large fraction. Looks like they are both divisible by 15 (hint: take a look at the chart we made earlier!) so let's try that.
#30/45 -: 15/15 = 2/3#