Question

The cost to produce a product is modeled by the function f(x) = 5x^2 − 70x + 258 where x is the number of products produced. Complete the square to determine the minimum cost of producing this product.

A. 5(x − 7)^2 + 13; The minimum cost to produce the product is $13.

B. 5(x − 7)^2 + 13; The minimum cost to produce the product is $7.

C. 5(x − 7)^2 + 258; The minimum cost to produce the product is $7.

D. 5(x − 7)^2 + 258; The minimum cost to produce the product is $258.

Answer 1

@jim_thompson5910

Answer 2

how far did you get?

Answer 3

This was my first question like this

Answer 4

what is the axis of symmetry in this case?

Answer 5

5(x-7)^2

Answer 6

hint: the axis of symmetry of ax^2 + bx + c is x = -b/(2a)

Answer 7

what is the axis of symmetry of 5x^2 − 70x + 258

Answer 8

5?

Answer 9

what are 'a' and 'b' in this case?

Answer 10

5 and 70

Answer 11

close

a = 5
b =-70

Answer 12

now plug those into x = -b/(2a)

Answer 13

Negative 700?

Answer 14

i dont think thats right

Answer 15

x = -b/(2a)

x = -(-70)/(2*5)

x = ???

Answer 16

-70?

Answer 17

no

Answer 18

-7?

Answer 19

try again

Answer 20

negative 70 divided by ten no?

Answer 21

postive 7?

Answer 22

yes it's positive 7

Answer 23

so h = 7

Answer 24

now that we know x = 7, plug it into the equation and tell me what you get

Answer 25

608?

Answer 26

that's way too high

Answer 27

5(7)^2 − 70(7) + 258 <--- plug it in like that right?

Answer 28

yes

Answer 29

giving you what?

Answer 30

is it anywhere in the hundreds?

Answer 31

you said 608 is high

Answer 32

yeah 608 is way too high

Answer 33

so if it was 300 or 400 it'd still be too high?

Answer 34

yes, it's a 2 digit number

Answer 35

13?

Answer 36

yes

Answer 37

so that's why the equation turns into

f(x) = 5(x-7)^2 + 13

Answer 38

Thank you, thanks alot

Answer 39

np

Answer 40

thats wrong

Answer 41

@stabar whats the answer then