Find the area of a triangle with base of 12 and height of 5a+7b. someone

If you answer right ill give brainliest, : )

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

Find the area of the unshaded square