Question

Given f(x) = x2 + 6x and g(x) = 3x2 + 12x, find (f – g)(x).

Answer 1

here is a simple breakdown:
f(x)=(x^2 +6x)
g(x)=(3x^2 +12x)

(f-g)(x)= (f(x))-(g(x))
(f-g)(x)= (x^2 +6x)-(3x^2 +12x)

can you get it from there?

Answer 2

combine like terms right?

Answer 3

Correct...

Answer 4

4x^2+18x

Answer 5

oops wait

Answer 6

2x^2+6x?

Answer 7

Remember first you need to distribute that '-' sign...

Answer 8

oh so then it's 4x^2+13x the second part?

Answer 9

so you'll have

x² - 3x² = ...?
and
6x - 12x = ...?

Answer 10

Just as john said, that negative sign gets distributed, then it is just a matter of combining like terms.

Answer 11

So you have

(x² +6x)-(3x² +12x)

After distributing that '-' sign into the second parenthesis you have

x² + 6x - 3x² - 12x

Now combine those...

Answer 12

ohh okay 2x^2-6x then

Answer 13

missing 1 thing still...

x² - 3x² = ...?

Answer 14

-2x^2 I mean

Answer 15

There we go...correct -2x² - 6x

Answer 16

thanks!

Answer 17

No problem!