How do you evaluate #-\frac { 5} { 3} -( - \frac { 7} { 5})#?

1 Answer
Meave60
Sep 1, 2017

#-5/3-(-7/5)=-4/15#

Refer to the explanation for the process.

Explanation:

#-5/3-(-7/5)#

In order to add or subtract fractions, they must have the same denominator, called the least common denominator (LCD). Since #3# and #5# are prime numbers, we can multiply them together to get the LCD. #3xx5=15#, so the LCD is #15#.

Each fraction must be multiplied by a multiplier that will give them both the denominator #15#. In this case, the multiplier is a fraction that equals #1#, which is a fraction that has the same numerator and denominator. For example #color(red)3/color(red)3=1#. In this way we create equivalent fractions that have the same value as the original fraction.

Simplify.

#-5/3+7/5#

Multiply each fraction by a multiplier that results in a denominator of #15#.

#-5/3xxcolor(teal)5/color(teal)5+7/5xxcolor(magenta)3/color(magenta)3#

Simplify.

#-25/15+21/15#

Simplify.

#-4/15#

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