Sum of polynomials are always polynomials.
Note that despite it's name, single constants, monomials, binomials, trinomials, and expressions with more than three terms are all polynomials.
For example,
0, π sqrt(2)x, 4x+2, x^2+3x+4, x^2-x^2, x^5+x/ π -1
are all polynomials.
What makes an expression NOT a polynomial?
Expressions that contain non-integer or negative powers of variables, rational functions, infinite series.
For example,
sqrt(x+1), 1/x+4, 1+x+ x^2/2!+x^3/3!+x^4/4!+...., (5x+3)/(6x+7)
are NOT polynomials.
Answer:
1). x = 81
2). x = 84
Step-by-step explanation:
1). By applying geometric mean theorem in the given triangle,

56x = (18√14)²
56x = 4536
x = 
x = 81
2). By applying geometric mean theorem,

16x = (8√21)²
16x = 1344
x = 
x = 84
Average speed = (total distance) / (total time)
Average speed = (192 km) / (8 hours) = 24 km per hour .
ab+bc>can is the correct answer