Question

V. Solve the following problem. Show your complete solution
A company's sales, in millions of peso, of electrical appliances can be modeled by S(x) = x + 16x2 + 25x + 576, where *
is the number of years since 2005. Estimate the sales for 2021.
Hints:
a. Use substitution method.
b. Count the years from 2005 to 2021. (2005 is year 1).
Solution:
Final Answer:​

Answer 1

STEP

1

:

Equation at the end of step 1

x2 • (x - 5)2 - 576 = 0

STEP

2

:

2.1 Evaluate : (x-5)2 = x2-10x+25

Checking for a perfect cube :

2.2 x4-10x3+25x2-576 is not a perfect cube

Trying to factor by pulling out :

2.3 Factoring: x4-10x3+25x2-576

Thoughtfully split the expression at hand into groups, each group having two terms :

Group 1: 25x2-576

Group 2: -10x3+x4

Pull out from each group separately :

Group 1: (25x2-576) • (1)

Group 2: (x-10) • (x3)