Choose 2 numbers whose sum is -2.6.

0.7
-14/5
0.3
1.0
0.2
-2 9/10
0.8
-3 3/10
-3 2/5
-18/5

1 answer

To find two numbers from the provided list that sum to -2.6, we first need to express -2.6 in a fraction for easier calculations.

-2.6 can be written as -26/10 or simplified as -13/5.

Now let's see if we can find two numbers from your list that add up to -13/5.

Here’s the list of numbers with their fractional equivalents:

  1. \( 0.7 = \frac{7}{10} \)
  2. \( -\frac{14}{5} \)
  3. \( 0.3 = \frac{3}{10} \)
  4. \( 1.0 = \frac{10}{10} \)
  5. \( 0.2 = \frac{2}{10} \)
  6. \( -2 \frac{9}{10} = -\frac{29}{10} \)
  7. \( 0.8 = \frac{8}{10} \)
  8. \( -3 \frac{3}{10} = -\frac{33}{10} \)
  9. \( -3 \frac{2}{5} = -\frac{17}{5} \)
  10. \( -\frac{18}{5} \)

Now, let’s check combinations:

  1. Combine \( -\frac{14}{5} \) with \( 0.8 = \frac{8}{10} = \frac{4}{5} \): \[ -\frac{14}{5} + \frac{4}{5} = -\frac{10}{5} = -2 \] (Not -2.6)

  2. Combine \( -\frac{14}{5} \) with \( -\frac{18}{5} \): \[ -\frac{14}{5} + -\frac{18}{5} = -\frac{32}{5} = -6.4 \] (Not -2.6)

  3. Combine \( -\frac{14}{5} \) with \( 0.3 = \frac{3}{10} \) (which is equivalent to \( \frac{6}{10} \)): \[ -\frac{14}{5} + \frac{3}{10} = -\frac{28}{10} + \frac{3}{10} = -\frac{25}{10} = -2.5 \] (Not -2.6)

  4. Combine \( -\frac{14}{5} \) with \( 0.2 = \frac{2}{10} \): \[ -\frac{14}{5} + \frac{2}{10} = -\frac{28}{10} + \frac{2}{10} = -\frac{26}{10} = -2.6 \]

Thus, the two numbers that sum to -2.6 are:

-14/5 and 0.2.