Question

If f(x) = 7x-4, find f(3)-2f(-2)

Answer 1

where do you need help for this? what is confusing?

Answer 2

\(f(x)=7x-4\), find \(f(3)-2f(-2)\).

Answer 3

\(f(x)=7x-4\), when you are asked to find the solution of \(f(c)\) of any function, where c is a number/constant or whatever, simply plug in what you have in these parentheses in \(x\) and solve.

Answer 4

Now can you apply what I just told you to your problem?

Answer 5

@qasaali Let her try :)

Answer 6

ok zepp

Answer 7

i try wait

Answer 8

E.g.:
Given \(\large f(x)=7x-4, \text{find f(c)}; f(c) = 7c-4\).

Answer 9

let me help her

Answer 10

You can do it >:D

Answer 11

i need a help guys

Answer 12

First can you find f(3)?

Answer 13

\(\large \text{Given }f(x) =7x-4, \text{Find f(c);} \\\large f(c)=7c-4\)
\(\large \text{Given }f(x) =7x-4, \text{Find f(3);} \\\large \text{?}\)

Answer 14

wait i almost get it

Answer 15

f(3)=7(3)-4
f(3)=21-4
f(3)=17

Answer 16

http://puu.sh/MawP

Answer 17

yeah i got 17 also

Answer 18

Great!

but your actual problem is to find \(f(3)-2f(-2)\), now you've understood the concept, this should be easy! :D

Answer 19

\(f(3)-2f(-2)\)

Value of f(x) when x = 3
minus
Twice the value of f(x) when x = -2

Answer 20

is the answer 73 ?

Answer 21

it looks like 17-2(-56) = 73

Answer 22

u c we have 21 for f(3) the second step would be finding 2f(-2)

Answer 23

\[\text{Given}~f(x) = 7x-4, \text{Find}~f(3)-2f(-2);\\\]\[\large \begin{align}
&=(7(3)-4))-2(7(-2)-4))\\
&=17-2(-14-4)\\
&=17-2(-18)\\
&=17+36\\
&=53



\end{align}\]

Answer 24

Umm

Answer 25

f(-2)=7(-2)-4
f(-2)=-14-4
f(-2)=-18*2
f(-2)=-36

Answer 26

therefore=21-36= -15

Answer 27

i got 53

Answer 28

@qasaali It's 17, not 21, and it's -(-36)

Answer 29

17-(-36)=17+36=53

Answer 30

17-2(-18) = 53

Answer 31

@glares25 Correct! Good job! :)

Answer 32

ok sorry for the silly mistake (-)*(-)=+
so the last answer will be 36+17=53

Answer 33

THANKS A LOT GUYS :D
i probably dont figured it out if u didn't help me :)

Answer 34

You are welcome :)