How do you use the LCD of 10 and 15 to solve #3/10 + 5/15#?

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Answer 1 · 2017-07-22T01:34:38

See a solution process below:

To add or subtract fractions they must be over a common denominator.

The Lowest Common Denominator of #10# and #15# is #30#

We can multiply each fraction by the appropriate form of #1# to put each fraction over this LCD:

#(3/3 xx 3/10) + (2/2 xx 5/15) =>#

#(3 xx 3)/(3 xx 10) + (2 xx 5)/(2 xx 15) =>#

#9/30 + 10/30#

We can now add the numerators over the common denominator:

#9/30 + 10/30 => (9 + 10)/30 =>#

#19/30#