18.The cross price elasticity of biscotti demand with respect to the price of Lattes is -0.70 (Lattes and biscotti are complementary goods).If the price of Lattes decreases 20%, what would you expect to happen to biscotti demand?

Possible answers:a.14% increase in biscotti demandb.44% decrease in biscotti demandc.30% decrease in biscotti demandd. 87.5% decrease in biscotti demande. 7.0% increase in biscotti demandf. 27% decrease in biscotti demand

19.Write the first derivative of the following function.

Y = 2X³ -3X² +2X -50

20.Write the first derivative of the following function.

Y = 5X^4/5 + 3X³ -2X^3/2 -10

Please show work on how you solved the problems.