Answer:
#1. x = -1
Answer = 8
#2. x = 1/5
Answer = 344/25
#3. x = 14
Answer = 13328
Explanation:
#1. a. plug in -1
f(-1)= (5(-1)^3) - (2(-1)^2 - (-1) + 14
b. Solve the exponents.
(5(-1)^3)
(5x-1)
(-5) - (2(-1)^2) - (-1) + 14
(2(-1)^2)
(2x1)
(-5) - (2) - (-1) +14
c. simplify.
(-5) - (2) + 1 + 14
-7 + 15
8
#2.
f(1/5)= (5(1/5)^3) - (2(1/5)^2 - (1/5) + 14
(5(1/5)^3)
(5 x 1/125)
(1/25) - (2(1/5)^2)
(2 x 1/25)
(2/25)
(1/25) - (2/25) - (1/5) +14
(-1/25) - (1/5) +14
Note: (1/5) turns into (5/25) so it can be subtracted.
-6/25 + 14
Note: 14 turns into 350/25 so it can be added.
350/25 - 6/25 = 344/25
#3.
f(14)= (5(14)^3) - (2(14)^2 - (14) + 14
Note: Normally you do the exponents first but I'm just going to casually take out the two 14s at the end cause they cancel each other out.
f(14)= (5(14)^3) - (2(14)^2)
( 5 (14^3))
(5 x 2744)
(13720) - (2(14^2))
(2 (14^2))
(2x196)
392
(13720) - 392
13328
Good Luck!