choose 2 numbers whose sum is about 9?

Question

-2.3
10 9/10
12 1/10
-2.1
10 4/5
-3.5
-2.8
-4.0
12 9/10
9 4/5
-1.0
12 1/2

Answer 1

To find two numbers whose sum is about 9, let's first convert the mixed numbers into decimals for easier calculation:

• \(10 \frac{9}{10} = 10.9\)
• \(12 \frac{1}{10} = 12.1\)
• \(10 \frac{4}{5} = 10.8\)
• \(12 \frac{9}{10} = 12.9\)
• \(9 \frac{4}{5} = 9.8\)
• \(12 \frac{1}{2} = 12.5\)

Now, let's look at the options:

-2.3
10.9
12.1
-2.1
10.8
-3.5
-2.8
-4.0
12.9
9.8
-1.0
12.5

Now we will find pairs that sum close to 9:

1. \(10.8\) and \(-1.0\):
   \(10.8 + (-1.0) = 9.8\)

2. \(10.9\) and \(-2.0\):
   \(10.9 + (-2.0) = 8.9\)

3. \(9.8\) and \(-0.0\):
   \(9.8 + (-0.0) = 9.8\)

Looking specifically for sums that are close to 9, pairs such as:

• \(10.8\) and \(-1.0\) (sum = 9.8)
• \(10.9\) and \(-2.0\) (sum = 8.9)

Given the options provided, two good choices whose sum is around 9 would be:

10.8 and -1.0 (sums to 9.8).