Answer:
x=27
Step-by-step explanation:
(2x-18)+(4x)=180 bc its a straight line
simplify
6x-18=180
-18 -18
6x=162
divide
x=27
Answer:
B is correct.
Step-by-step explanation:
Quadratic Expression (Standard Form) is:

To say it simply, the expression must have 2 as the highest degree.
This means that if there are any higher or lower degrees than 2 then they are not quadratic expression.
A choice is not quadratic expression because it has 1 as the highest degree.
B choice is correct because 2 is the highest degree.
C choice is wrong because 3 is the highest degree.
D choice is wrong because it is not a polynomial.
Therefore, B is correct.