If you multiply all the square inches, you would get 15,015
To see how they are related, let us solve the two equations.
FIRST EQUATION



SECOND EQUATION



Hence the solutions to the two equations are ADDITIVE INVERSE of each other.
40 boxes would weigh would weigh 120 pounds
(4x−101)(2x+3)
Apply the distributive property by multiplying each term of 4x−101 by each term of 2x+3.
8x²+12x−202x−303
Combine 12x and −202x.
8x²−190x−303