3. Demuestre que d
dt (A ∙
dB
dt −
dA
dt ∙ B) = A
d
2B
ds
2 −
d
2A
ds2
∙ B
donde A y B son funciones diferenciales de s

The hawaiian alphabet has 12 letters. how many permutations are posible for each number of letters?

Which of the following is most likely the next step in the series? a3z, b6y, c9x, d12w, е15v, f18u

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil