A food company delivers its fruit in two types of boxes, large a small. A delivery of 7 large boxes and 9 small boxes has a total weight of 273 kg. A delivery of five large boxes and 3 small boxes and a total of 141 kg how much does each type of box weigh

Let L and S represent the weights of large and small boxes, respectively. The problem statement gives rise to two equations:

... 7L + 9S = 273

... 5L + 3S = 141

You can solve these equations various ways. Using "elimination", we can multiply the second equation by 3 and subtract the first equation.

... 3 (5L + 3S) - (7L + 9S) = 3 (141) - (273)

... 8L = 150

... L = 150/8 = 18.75

Then we can substitute into either equation to find S. Let's use the second one.

... 5*18.75 + 3S = 141

... S = (141 - 93.75) / 3 = 15.75

A large box weighs 18.75 kg; a small box weighs 15.75 kg.