(p+q)^2-r^2/(q+r)^2-p^2

Solve this please

Use the elimination method to solve the system of equations -x+5y=-4 and 4x+3y=16

Ivan and jeff buy a package of 8 pens for $4.00. ivan wants 5 of the pens, and jeff wants 3.how much should each student pay?

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