Step-by-step explanation:
for any matrix multiplication number of columns of first matrix should be equal to number of rows of second matrix.
For AB
A has 3 columns and B has 3 rows so it matches . Hence can be multiplied.
For BA
B has 2 columns and A has 2 rows it also matches so can be multiplied
It takes the son one and half hours to clean the house. To find this you need the equations F+S=2 and F+1=S. (F=father and S=son) You take the F+1 and substitute it in for S in F+S to get F+(F+1)=2. Then you combined like factors, 2F+1=2, and simplify to get F=.5hr. After this you plug .5 in to F+1=S to get (.5)+1=S, meaning it takes the son 1.5 hour to clean the house.
You divide and get 3/7 meters per second
This kinda easy. Every 3 yellow drops is 4 blue drops, so here's the answer. 3 = 4, 6 = 8, 9 = 12, 12 = 16. so you would need 16 blue drops.
The answer to your question is 260,100