The price to ship a box varies directly as the weight of the box in pounds. a box that weighs 4 pounds costs $4.20 to ship. what would it cost to ship a second box that weighs 30 pounds? a. $28.57 b. $126.00 c. $7.88 d. $31.50

31.50$ 
No prob for helping i hope it helps u :)

I think you would have to divide i think

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.