Answer:
a.

b.

Step-by-step explanation:
The formula for calculate the area of a rectangle is:

Where "l" is the lenght and "w" is the width
a. We know that the kitchen measures 3.75 meters by 4.2 meters; then we can say that:

Therefore, substituting these values into the formula, we get that the area of the kitchen is:

b. The area of the living room is one and a half times (1.5 times) that of the kitchen, this is:

Therefore, the total of the living room and the kitchen is:
