I am going to assume that the equation was supposed to be 
Answer:
It is a polynomial. It is a binomial and it has a degree of 5.
Step-by-step explanation:
A polynomial is an expression consisting of variables and coefficients, that involves only the operations of addition, subtraction, multiplication, and non-negative integer exponentiation of variables so 
will be considered a polynomial.
A binomial is a polynomial with 2 terms.
The degree of a polynomial is the highest exponent in it which in this equation is 5.
Answer:
6 units
Step-by-step explanation:
A = lw
l = w + 2
48 = lw
48 = (w + 2)w
48 = w² + 2w
0 = w² + 2w - 48
Quadratic equation results =
w = 6 or w = -8
But the measure could not be negative, therefore w = 6
You can use F.O.I.L. for this, which if you don't know stands for first outer inner last, so multiply the first in each parentheses, then the outer, then the inner, then the last. yours would be 3*5+3*√7+(-√7)*5+(-√7)*√7 => 15+3√7-5√7-7 => 8-2√7
Final answer:
8-2√7
Hope I could help :)