What is the solution to the system of equations? use the substitution method to solve. 6=−4x+y −5x−y=21 enter your answer in the boxes. ( , )

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days