Question

A biologist studied the populations of black bear and brown bears over a 10-year period. The biologist modeled the populations, in thousands, with the following polynomials where x is time, in years.black bears: 2.3x2 – 5.6x + 2.3brown bears: 2.4x2 + 7.2x + 0.97What polynomial models the total number of brown and black bears? A. 4.7x^2 + 1.6x + 3.27 B. 4.7x^2 – 1.6x – 3.37 C. 4.7x^2 + 1.6x – 3.37 D.4.7x^2 – 1.6x + 3.37

Answer 1

the general rule of additionnig polynomials is
p(x)+q(x)= (p+q)(x), that means, the coefficient of the terms which have same degree can be additionned directly.
black bears: 2.3x2 – 5.6x + 2.3
brown bears: 2.4x2 + 7.2x + 0.97
so the total number of brown and black bears is
(2.3+2.4)x²+(7.2-5.6)x+2.3+0.97=4.7x²+1.6x+3.27
so the true answer is A. 4.7x^2 + 1.6x + 3.27