Question

Help please and show the steps! thank you!​

Answer 1

#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!