Answer:
5-10(0.8-3/5) = 3
Explanation:
We need to Simplify the following expression: 5-10(0.8-3/5)
First, we need to solve the parenthesis. Given that we need to substract a fraction from a decimal number, we convert the number '0.8' to a fraction as follows:

Now we solve the parenthesis:
⇒

The new expression is:
⇒
⇒ 3
Therefore, 5-10(0.8-3/5) = 3