Question

Subtracting Functions
help
if f(x)=3x-2 and g(x)=x^2-4x+1,find (f-g)(x)

Answer 1

please help

Answer 2

I know the answer But I don't know how to get there

Answer 3

First i would write equation in one line so that i can see what i am subtract
3x-2- (x^2 - 4x+1)
Then i would distribute the negative sign so it would be
3x -2 -x^2 + 4x -1

Answer 4

solve it that way.

Answer 5

i guess then you can put the like terms together.
so -x^2 +4x +3x -1 -2

Answer 6

-x^2 + 7x -3 should be the answer. did you get that?

Answer 7

I don't understand where -x^2 came from. Wouldn't 3x-x^2 be 2x^2?

Answer 8

I think I need a equation calculator

Answer 9

@bobristic

Answer 10

no 3x-x^2 would not be 2x^2 because 3x is a term to the power of one (3x^1) and to subtract a variable you need to have the same powerand -x^2 has the power of two.
the -x^2 came from when you distributed the - (x^2 - 4x+1). the negative outside of the parenthesis is distributed to all the terms in the parenthesis. x^2 was positive and because the - was distributed it was now x^2.

Answer 11

what do you mean by equation calculator?

Answer 12

Thats a subtraction sign not a negative sign

Answer 13

you called it a negative sign...I think you maybe be confusing me or your confused

Answer 14

well i know when you say 3x-2- (x^2 - 4x+1) it is just shorten version of writing 3x-2 + (-1)(x^2 - 4x+1)

Answer 15

is it though in this case?Because I'm specifically subtracting

Answer 16

what do you mean though? to be honest negative sign or subration is practically the same thing .
Could you rewrite what you are confused about because im confused about what you are confused about.

Answer 17

Ok hold on

Answer 18

I just dont understand where -x^2 came from and "7x" came from when I'm supposed to be subtracting if f(x)=3x-2 and g(x)=x^2-4x+1 find (f-g)(x)

Answer 19

okay so when you are finding (f-g)(x), you are subtracting f(x) - g(x). then you replace the function with the equation.
3x-2 - (x^2-4+1)
do you understand so far?

Answer 20

yea

Answer 21

okay. then you got to make the parenthesis go away. but there is a subtraction/negative sign in front of it, there for you have to give that negative sign to every thing(terms) a negative symbol.
3x-2 -(x^2) -(-4x) -(1).
and -(-) is just positive so
3x-2 -x^2 +4x -1.
so far with me?

Answer 22

yea

Answer 23

then you have to add all the like terms, which are number with variables with same same power. 3x has the power of 1.
-2 has the power of 0
-x^2 has the power of 2
+4x has the power of 1
-1 has the power of 0

Answer 24

then put the number in highest power to the lowest power
-x^2 +3x+4x -2 -1

Answer 25

then you can see the like terms together and you add/subtract the terms.
so 3x+ 4x = 7x and -2-1= -3
then write down the equation with the term added.
-x^2 +7x-3

Answer 26

is there a simpler way to do this?

Answer 27

no offense

Answer 28

well this is simple ... if i was there physically i would be able to explain better..