Add -1 3/10 + (-4 2/15)

A. -2 5/6
B. -5 1/6
C. -5 13/30
D. -5 1/5

1 answer

To add the fractions \(-1 \frac{3}{10} + (-4 \frac{2}{15})\), we can first convert both mixed numbers into improper fractions.

  1. Convert \(-1 \frac{3}{10}\) to an improper fraction: \[ -1 \frac{3}{10} = -\left(1 \cdot 10 + 3\right)/10 = -\frac{10 + 3}{10} = -\frac{13}{10} \]

  2. Convert \(-4 \frac{2}{15}\) to an improper fraction: \[ -4 \frac{2}{15} = -\left(4 \cdot 15 + 2\right)/15 = -\frac{60 + 2}{15} = -\frac{62}{15} \]

Now we need to add \(-\frac{13}{10}\) and \(-\frac{62}{15}\). To do this, we need a common denominator. The least common multiple of 10 and 15 is 30.

  1. Convert \(-\frac{13}{10}\) to have a denominator of 30: \[ -\frac{13}{10} = -\frac{13 \times 3}{10 \times 3} = -\frac{39}{30} \]

  2. Convert \(-\frac{62}{15}\) to have a denominator of 30: \[ -\frac{62}{15} = -\frac{62 \times 2}{15 \times 2} = -\frac{124}{30} \]

Now we can add the two fractions: \[ -\frac{39}{30} + -\frac{124}{30} = -\frac{39 + 124}{30} = -\frac{163}{30} \]

Now, to express \(-\frac{163}{30}\) as a mixed number:

  • Divide 163 by 30.
  • 30 goes into 163 five times (since \(30 \times 5 = 150\)), and we have a remainder of \(163 - 150 = 13\).

So, \(-\frac{163}{30} = -5 \frac{13}{30}\).

Thus, the answer is: \[ \boxed{-5 \frac{13}{30}} \]

This corresponds to option C.