5 large box weight = 93.75
7 large box weight = 131.25
3 small box weight = 47.25
9 small box weight = 141.75
As per given question , let us consider large boxes x and small boxes y
then we will 2 algebric equations from the question
5x + 3y = 141 (1)
7x + 9y = 273 (2)
now by using elimination method we will eliminate y term and will get x value , x = 18.75
now putting x value in equation 1 we will get y value , y = 15.75
5x + 3y = 141
18.75 × 5 + 3y = 141
93.75 + 3y = 141
3y = 47.25
y = 15.75
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