1) Prove that if A⊨tautB and C⊨tautD then A∨C⊨tautB∨D . 2) Show that the formulae A≡⊥ and ¬A are tautologically equivalent.

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

Write an algebraic expression to match each statement a. four less than 8 times a number b. twice the difference of a number and six c. nine from a number squared

1. find the area of the unshaded square 2. find the area of the large square 3. what is the area of the frame represented by the shaded region show