Find ds/dt if s= (t/ 7t + 9)

10 points to the best answer! :)

assuming u mean s= ( t / (7t + 9) )

ds/dt = [ (7t + 9) * 1 - t * 7 ] / [ (7t + 9)^2 ]

ds/dt = [ (7t + 9) - 7t ] / [ (7t + 9)^2 ]

ds/dt = [ 7t + 9 - 7t ] / [ (7t + 9)^2 ]

ds/dt = (9 / (7t + 9)^2 )

just apply quotient rule

so ds/dt = [(7t+9)-7t]/(7t+9)^2 = 9/(7t+9)^2

S=64/7