Question

closed

Answer 1

help

Answer 2

can you post a screenshot of this problem please?

Answer 3

thats all it has

Answer 4

are there exponents at all?

Answer 5

thanks that clears things up for me

Answer 6

do you see how the table is filled out so far? For instance, do you agree that if x = 0 then g(x) = 1 ?

Answer 7

yes

Answer 8

what is g(x) when x = 2?

Answer 9

5

Answer 10

i mean 6

Answer 11

one moment

Answer 12

Replace every x with 2
\[\Large g(x) = 5^{x}\]
\[\Large g({\color{red}{x}}) = 5^{{\color{red}{x}}}\]
\[\Large g({\color{red}{2}}) = 5^{{\color{red}{2}}}\]
\[\Large g(2) = 5*5\]
\[\Large g(2) = 25\]
Notice how \(\Large 5^2\) is equal to 5*5 = 25 and NOT 5*2 = 10

Answer 13

so its D

Answer 14

or C

Answer 15

\(\Large 5^2\) means multiply the base (5) by itself twice
\(\Large 5^3\) means multiply the base 5 by itself 3 times
and so on

Answer 16

what is \(\Large 5^3\) equal to?

Answer 17

15

Answer 18

no it's not 5*3

\(\Large 5^3\) means we have three copies of 5 multiplied together

\(\Large 5^3 = 5*5*5 = ???\)

Answer 19

125

Answer 20

so it is D

Answer 21

good, how about \(\Large 5^4\)? What is that equal to?

Answer 22

let's ignore the answer choices for now

Answer 23

625

Answer 24

you got it

Answer 25

ok so the positive exponents tell us how many copies to multiply

the negative exponents are basically the opposite

Answer 26

so 5 to the power of -2 would be 0.04

Answer 27

we can use the rule described here

http://www.purplemath.com/modules/exponent2.htm

to say

\[\Large 5^{-1} = \frac{1}{5^1} = \frac{1}{5} = 0.2\]

Answer 28

another example,

\[\Large 5^{-2} = \frac{1}{5^2} = \frac{1}{25} = 0.04\]

Answer 29

making sense?

Answer 30

yes

Answer 31

so far, we've only filled out the g(x) column of the table

Answer 32

do you know how to fill out the f(x) column?

Answer 33

9x + 7 ?

Answer 34

9x+7 means

9 times _____ + 7

where you can fill in the blank with any number you want

Answer 35

the values you must pick are given in the x column, so -2 through to +2

Answer 36

they have already done -2 and -1 for you

for example, if x = -2, then

y = 9*x + 7
y = 9*(-2) + 7 ... replaced x with -2
y = -18+7
y = -11

so that explains why -11 in the f(x) column is on the same row as x = -2

Answer 37

hopefully you can see how x = -2 leads to f(x) = -11 ?

Answer 38

yes

Answer 39

so D is wrong

Answer 40

if x = 0, then what is f(x) equal to?

Answer 41

1

Answer 42

how did you get 1?

Answer 43

wait no i read chart wrong

Answer 44

you probably read the g(x) column by accident

Answer 45

16

Answer 46

i did 9x + 7 with x as 0

Answer 47

replace that x with 0 and then evaluate

Answer 48

9*x + 7 = 9*0 + 7 = ???

Answer 49

again I'm asking what the f(x) value is when x = 0

Answer 50

x=-2 , 5(-2)=-10
x=-1 , 5(-1)= -5
x=0 , 5(0)=0
x=1 5(1)=5
x=2 5(2)=10

Answer 51

you're making a mistake because it's an exponent in g(x)

Answer 52

it's not 5*(0) = 0

it's actually 5^0 = 1

Answer 53

oh

Answer 54

I'm asking about f(x) though. When x = 0, what is the value of f(x) ?

Answer 55

-1

Answer 56

replace that x with 0 and then evaluate

9*x + 7 = 9*0 + 7 = ???

Answer 57

i think it is A because fx -1 gx 0

Answer 58

let's only focus on the answer choices after we fill out the table

Answer 59

what is 9*0 equal to?

Answer 60

9

Answer 61

0

Answer 62

no

Answer 63

yes 0

Answer 64

so 9*0+7 is equal to what?

Answer 65

7?

Answer 66

yep, so when x = 0, we'll have 7 in the f(x) column

Answer 67

ok

Answer 68

when x = 1, what goes in the f(x) column?

Answer 69

16

Answer 70

good

Answer 71

when x = 2, what goes in the f(x) column?

Answer 72

25

Answer 73

very nice

so the finished table looks like this (see attached)

Answer 74

the solution to f(x) = g(x) is the x value that corresponds to when f(x) and g(x) are the same number. So look for where the rows match up and have the same number

Answer 75

Its D !

Answer 76

no 25 is not the x value, but I can see why you think so

Answer 77

25 is the f(x) and g(x) value but not x itself

Answer 78

when x = _____, f(x) = 25 and g(x) = 25 so at this x value, f(x) = g(x)

Answer 79

oh its 2

Answer 80

yep, x = 2 is the final answer

Answer 81

thanks

Answer 82

plug in x = 2 and both functions spit out the same output, which is 25