simplify : 81s^2/36s^2
= ( 81 / 36 ) ( s^2 / s^2 ) = ( 9 / 4 ) 1 = 9 / 4 = 2.25.
\(\boxed{\frac{81\times s^2}{36\times s^2}= \frac{81}{36}\times \frac{s^2}{s^2}=2 \frac{9}{36}\times 1=2\frac{1}{4}=2,25}\)
