Question

Last 2..

Answer 1

Solve.

An investment is worth $3486 in 1995. By 2000 it has grown to $6441. Let y be the value of the investment in the year x, where x = 0 represents 1995. Write a linear equation that models the value of the investment in the year x.

Answer 2

@jim_thompson5910

Answer 3

`x = 0 represents 1995`
in the year 2000, what is x?

Answer 4

x is 5

Answer 5

yes

Answer 6

`An investment is worth $3486 in 1995`

x = 0 and y = 3486

the point (0,3486) is on the graph

Answer 7

`By 2000 it has grown to $6441`
the point (5,6441) is on the graph

Answer 8

use the slope formula to find the slope through (0,3486) and (5,6441).

Answer 9

Okay.

Answer 10

591

Answer 11

yes

Answer 12

m = 591 is the slope
b = 3486 since we know (0,3486) is on the graph

Answer 13

plug those into y = mx+b

Answer 14

The equation is y=591x+3486

Answer 15

yes

Answer 16

Okay. One more.

Answer 17

38. Find the domain of the indicated combined function.

Find the domain of (fg)(x) when f(x) = square root 5x+8 and g(x) = .square root 7x-9

Answer 18

Ive never done a problem like this with square root so im not sure where to start

Answer 19

Normally id plug them in next to each other and multiple.

Answer 20

first solve 5x+8 >= 0 for x

Answer 21

x>/ -8/5

Answer 22

type `>=` to mean "greater than or equal to"

Answer 23

I agree, it's `x >= -8/5`

Answer 24

now solve `7x-9 > 0` for x

Answer 25

9/7

Answer 26

there is NO underline because we don't want 7x-9 to be 0

Answer 27

`x > 9/7` I think you mean

Answer 28

plot `x >= -8/5` and `x > 9/7` on the same number line

then shade the region where they both overlap

Answer 29

Yes.

Answer 30

The domain is [9/7 , infinity)

Answer 31

if x = 9/7, then the denominator would be 0. But we cannot divide by 0

Answer 32

Um okay..

Answer 33

so we have to kick out 9/7 from the domain

Answer 34

[0,infinity)

Answer 35

you were on the right track, just change the `[` to `(`

Answer 36

Domain: `(9/7, infinity)`

Answer 37

I only have options of-
[9/7, infinity)
[0,infinity)

Answer 38

hmm so strange. That has to be a typo because 9/7 isn't part of the domain

Answer 39

oh wait, it's (fg)(x) and not (f/g)(x)

so yeah 9/7 is allowed

Answer 40

Okay. Thank you.

Answer 41

no problem