6+× is an example of ? a variable an expression a constant a formula

How can we find the measure of an exterior angle if we know the measurement of an interior angle

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10

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