If the product of two numbers is positive then the two numbers must both be positive true or false

Let f (x) = x e8x. find a formula for the nth derivative of f, where n is any positive integer. use x and n in your answer if needed. f (n)(x) =

Each month, a shopkeeper spends 5x + 14 dollars on rent and electricity. if he spends 3x−5 dollars on rent, how much does he spend on electricity? for which value(s) of x is the amount the shopkeeper spends on electricity less than $100? explain how you found the value(s).

Hardest math question of all time can you solve the equation. check for extraneous solutions.9∣9-8x∣ = 2x+3