Answer:
Which i think is the first one, there may just be a typing error.
Step-by-step explanation:
A polynomial of order n has the following format:

In which a is the leading coefficient,
are the roots.
If a root appears m times, they are said to have multiplicity m.
Leading coefficient of 1 and roots 21 and 31 with multiplicity 1

So the correct answer is:

Which i think is the first one, there may just be a typing error.
Answer:
512ft³
Step-by-step explanation:
If the cube its sides of all 8 feet, then the length, width, and height is 8 feet. Then, multiply 8 by 8 you get 64 and then multiply 64 by 8 to get 512.
Answer:
10 pounds.
Step-by-step explanation:
Let x pounds be the amount of mixed nuts we require.
Amount of peanuts in this mix = 0.70x pounds. Amount of peanuts in the 20% mix = 0.20*15 = 3 pounds.
So we have the equation:-
0.70 x + 3 = 0.40(x + 15)
0.70 x + 3 = 0.40(x + 15)
0.70x + 3 = 0.40x + 6
0.70x - 0.40x = 6 - 3
0.30x = 3
x = 10.