The sales tax on a TV set that costs $450 is $31.50. Find the percent of Sales Tax.

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

Solve the following simultaneous equation by using an algebraic method (either substitution or elimination) 2x + 3y=-4 4x-y=11