Answer:
3(3+x)=9+3x, or B
Explanation:
From the diagram, we can see that there are 3 rows of one x and 3 ones each.
Therefore, we can make the equation 3(3+x)
Then we could either count the blocks out to get 9+3x or just solve the above equation.
So, the answer would be 3(3+x)=9+3x, or B