Answer: 6x + 3
Explanation:
to find the area of a rectangle, simply multiply the long side by the short side.
3(2x + 1) = 6x + 3
If you know the value of x, you can plug that into 6x + 3 and get a more accurate answer.
For example, if x = 2, then:
6(2) + 3 = 12 + 3 = 15