Answer: The answer is

Step-by-step explanation: Given that Vishal wants to burn at least 2,400 calories during weekly hours. He burns 400 calories per hour swimming and 600 calories per hour rollerblading.
Let 'x' and 'y' represents the number of hours Vishal swims and rollerblades respectively.
Also given that Vishal swims 3 hours, so total number of calories he burnt while swimming is given by

Therefore, in order to burn at least 2,400 calories, we must have

Thus, the number of hours Vishal spent rollerblading is represented by
