PLEASE HELP ME! IS THIS CORRECT?

The sum of two numbers is 0. twice the smaller number subtracted from 3 times the larger number is 10. let x represent the larger number and y represent the smaller number. what is the equation

What is the value of -3/4 to the 4th power? -256/81 -81/256 81/256 256/81

Situation: . find the substance's half-life, in days. round your answer to the nearest tenth. a 11 gram sample of a substance that's used to treat thyroid disorders has a k. value of 0.1247. enter the correct answer n - noekt done no - initial mass (at time t = 0) n - mass at timet k a positive constant that depends on the substance itself and on the units used to measure time t= time, in days