Simplify (2xy)*(5yz) 2,8 x'z y y=-8 11 Simplify and Z = 10 then evaluate for X = 4,1 12 - Evaluate 64 without using a calculator. 52 13 Solve for x in the equation x = 32. Assume x is positive. 14 Solve the equation 23*+4 = 4 algebraically. 15 - Solve the equation 22x-3 = 128* algebraically. 16 - The volume, V cubic centimetres, of a melting snowball after / hours in the sun is given by the equation V=800(0.74)'. Estimate the number of hours it takes for the volume to decrease to 300 cm. 19 The mass, M, of ibuprofen in the bloodstream is given by the equation MI(0.69), where I is the initial dose and t is the number of hours since the dose. Suppose a patient is given an initial dose of 250 mg. When will the amount of ibuprofen in the bloodstream be reduced by a factor of one-half? Round your answer to the nearest tenth of an hour.