To find two numbers whose sum is -2.6, we can convert -2.6 into a fraction for easier calculation.
-2.6 can be expressed as \(-\frac{26}{10}\) or simplified to \(-\frac{13}{5}\).
Now let's consider the options provided:
- \(1.0\) (which is \(1\))
- \(0.8\) (which is \(\frac{8}{10}\) or \(\frac{4}{5}\))
- \(-3 \frac{2}{5}\) (which is \(-\frac{17}{5}\))
- \(-\frac{18}{5}\)
Now, we can check the pairs:
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Pair (1.0 and -3 2/5): \[ 1.0 + -\frac{17}{5} = 1 - \frac{17}{5} = \frac{5}{5} - \frac{17}{5} = -\frac{12}{5} \quad \text{(not -2.6)} \]
-
Pair (1.0 and -18/5): \[ 1.0 + -\frac{18}{5} = 1 - \frac{18}{5} = \frac{5}{5} - \frac{18}{5} = -\frac{13}{5} \quad \text{(correct)} \]
So, \(1.0\) and \(-\frac{18}{5}\) will satisfy the sum of \(-2.6\).
Thus, the two numbers whose sum is -2.6 are 1.0 and -18/5.