2+5

To solve the first problem on the image:

1a. Compute: (6.5 - 9.9) · 2.5

First, calculate inside the parentheses: 6.5 - 9.9 = -3.4

Now, multiply by 2.5: -3.4 · 2.5 = -8.5

The answer to 1a is -8.5.