The correct answer is -b+12
The degree of a polynomial is the highest power of its terms.
The power of a term is the sum of the powers of all the variables in a term.
A polynomial is written starting with the greatest power in standard form.
In the first case, the power of the first term is 3, the power of the second is 3 (2 from x + 1 from y) but the power of x has decreased so it is the second term, and then so on.
In the second case, the power is starting form 2 and then increasing to 3. This is incorrect.
Therefore, Marcus' suggestion is correct.
Answer:

Step-by-step explanation:

All the terms in this polynomial are divisible by 3. Factor 3 out of this polynomial:

Now, factor inside the parentheses by grouping:

We knew to split the +2x up into -1x and 3x because -1 and 3 multiply to get -3, which is the last value in the polynomial.

Therefore, the final factored polynomial is
.
All sides of an equilateral triangle are equal, so all three sides are 9 cm.
To find h, use the pythagorean theorem. This requires use of only one right triangle, where we use b as our h.
a^2+b^2=c^2
(4.5)^2+b^2=(9)^2
(20.25)+b^2=(81)
b^2=(81/20.25) or 4
square root both sides
b=2