If 6 times a number is added to -4, the result is 10 times the number. find the number.

the number is - 1

let the number be n then 6 times the number is 6n and added to -4 is

- 4 + 6n = 10n ( equal to 10 times the number )

subtract 6n from both sides

- 4 = 4n ( divide both sides by 4 )

= n , hence n = - 1

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50