Question

Add or subtract. Express simplest form 1 2/5 - (-1 2/15

Answer 1

Its 2 8/15 Conversion a mixed number 1 2
5
to a improper fraction: 1 2/5 = 1 2
5
= 1 · 5 + 2
5
= 5 + 2
5
= 7
5


To find new numerator:
a) Multiply the whole number 1 by the denominator 5. Whole number 1 equally 1 * 5
5
= 5
5

b) Add the answer from previous step 5 to the numerator 2. New numerator is 5 + 2 = 7
c) Write previous answer (new numerator 7) over the denominator 5.

One and two fifths is seven fifths
Conversion a mixed number -1 2
15
to a improper fraction: -1 2/15 = -1 2
15
= -1 · 15 + (-2)
15
= -15 + (-2)
15
= -17
15


To find new numerator:
a) Multiply the whole number -1 by the denominator 15. Whole number -1 equally -1 * 15
15
= -15
15

b) Add the answer from previous step -15 to the numerator 2. New numerator is -15 + 2 = -13
c) Write previous answer (new numerator -13) over the denominator 15.

Minus one and two fifteenths is minus thirteen fifteenth
Subtract: 7
5
- (-17
15
) = 7 · 3
5 · 3
- (-17)
15
= 21
15
- (-17
15
) = 21 - (-17)
15
= 38
15

The common denominator you can calculate as the least common multiple of the both denominators - LCM(5, 15) = 15. The fraction result cannot be further simplified by cancelling.
In words - seven fifths minus minus seventeen fifteenth = thirty-eight fifteenths.