Because the speed has formula of distance divide time = m/s
and the acceleration is speed /time so (m/s)/s = m/(s*s) = m/s^2
hope this is understandably sure easy for you
The length of the dollhouse is 156 square inches
Think of 6y as
y + y + y + y + y + y
Now subtract a y from that.
y + y + y + y + y + y - y = y + y + y + y + y = 5y