Question

The table below shows some values of f(x) and g(x) for different values of x:
x f(x)=2x+24 g(x)=5(0.5)^x
-2 20
-1
0 5
1 2.5
2 28

Complete the chart and determine the solution of the equation f(x) = g(x)

a) x = -2
b) x = -1
c) x = 1
d) x = 20

Answer 1

soooo confused guys pleeeasee help

Answer 2

please if x=20 what is f(x)?

Answer 3

20?

Answer 4

sorry I wanted say if x=-2, what is f(x)?

Answer 5

you have to substitute x=-2 into f(x), namely:
f(-2)=2*(-2)+24=20
so what is g(x) when x=-2?

Answer 6

you have to substitute x=-2 into g(x), namely:
\[g(-2)=5*\left( \frac{ 1 }{ 2 } \right)^{-2}=5*2^{2}=5*4=20\]
is it clear, please?

Answer 7

yes

Answer 8

ok! now we have to try with x=-1
so what is f(-1), please?

Answer 9

we have:
\[f(-1)=2*(-1)+24=-2+24=22\]
is it right?

Answer 10

yes

Answer 11

and g(-1), is:
\[g(-1)=5*\left( \frac{ 1 }{ 2 } \right)^{-1}5*2=10\]

Answer 12

oops...\[g(-1)=5*\left( \frac{ 1 }{ 2 } \right)^{-1}=5*2=10\]

Answer 13

ok so would the answer be B?

Answer 14

no, because f(-1)=22 and g(-1)=10, and 22 is not equal to 10

Answer 15

we have to try with x=1

Answer 16

so:
\[f(1)=2*1+24=2+24=26\]

Answer 17

and:
\[g(1)=5*\left( \frac{ 1 }{ 2 } \right)^{1}=5*\frac{ 1 }{ 2 }=\frac{ 5 }{ 2 }\]

Answer 18

so it is not x=1

Answer 19

now we try with x=2

Answer 20

we have:
\[f(2)=2*2+24=4+24=28\]

Answer 21

and:
\[g(2)=5*\left( \frac{ 1 }{ 2 } \right)^{2}=5*\frac{ 1 }{ 4 }=\frac{ 5 }{ 4 }\]

Answer 22

so it is not x=2

Answer 23

im gonna guess c then

Answer 24

I don't think because f(1)=26 and g(1)=5/2=2.5

Answer 25

ok so d ?

Answer 26

if x=20
we have:
\[f(20)=2*20+24=40+24=64\]

Answer 27

and:
\[g(20)=5*\left( \frac{ 1 }{ 2 } \right)^{20}\neq 64\]

Answer 28

ohh i get it but which one is it? im sorry this thing is timed so i kinda have to hurry

Answer 29

sorry, it is x=-2, because f(-2)=20 and g(-2)=20

Answer 30

ok thank you so much !!

Answer 31

thank you!