Just multiply all of them because Volume = Length x Width x Height. So it's 8.5 x 4.5 x 3.75. That equals 143.4375. Cubic inches is just there after you multiply, so you don't have to convert anything. So it's 143.4375 cubic inches.
The numbers are both equal because, 6.80 is six and eight hundredths, and 6.8 is six and eight tenths. When writing decimals any zero added to the end of the number has no value, 8/10 as a fraction is equal to 80/100 if simplified, so Nicky and Marta wrote equal numbers. :)
This is just like the other problem. The coefficient infront of the b which is "2" is your constant of proportionality. It makes the relationship between the number of bulbs and flowers signaling that for every flower there has to be 2 bulbs.
3xy + 10xy - 5x + 2x - 2yx
Add 3xy to 10xy
13xy - 5x + 2x - 2yx
Add -5x to 2x
Final Answer: B.) 13xy -3x - 2yx