Looking at number 4, you first have to look at the information that you have:
On tuesday he practiced for 1 5/6 hrs
Monday he practiced for 7/10 hrs
He is supposed to practice for 1 1/4 hr.
You could write questions like:
How much more did Marco practice on Tuesday than he is supposed to practice?
This works because it does indeed involve subtraction, you would be subtracting the amount that he should have practiced from the amount of time that he did practice.
If I didn't answer the question, please message me and I will clarify!
1/10 you find a common denominator and add them together which is 36 and simplify it down
You need to categorize the similar terms with the same exponential.
Here, 3 terms can be categorized: x^3, x^2 and constant
Then you simply manipulate the coefficient:
(5-9)x^3 + (-7+4)x^2 + (6+1) = -4x^3 - 3x^2 + 7
Volume is L x W x H.
Original volume: 40 x 60 x 50 = 120,000 cubic mm.
New Volume: 44 x 60 x 50 = 132,000 cubic mm
Change in volume: 132,000 - 120,000 = 12,000 cubic mm
