Question

f(x+7)=x^2-4x-9

Answer 1

in the function, anywhere there is an x, substitute an (x+7) in

Answer 2

f(x+7)=(x+7)^2-4(x+7)-9

Answer 3

how do you solve for that? i foiled (x+7)^2 distributed -4(x+7) and then subtracted -9 and i got x^2+10+40 but thats not right. I dont know what im doing wrong

Answer 4

how did you foil (x+7)^2

Answer 5

what did you get when you foiled?

Answer 6

x^2+14x+49

Answer 7

okay so then where did the 14x go when you solved?

Answer 8

f(x+7)=x^2+14x+49 -4x-28-9

Answer 9

i substracted 4x and it became a 10x

Answer 10

yes, just like that

Answer 11

okay, so your left with f(x+7)= x^2-10x+49-28-9

Answer 12

what is 49-28-9?

Answer 13

30

Answer 14

try again

Answer 15

12 haha

Answer 16

right, so f(x+7)= x^2-10x+49-28-9 --> =x^2-10x+12

Answer 17

does that make sense to you?

Answer 18

yeah it does thank you!

Answer 19

welcome :)

Answer 20

wait...
is the problem to find f(x+7) = ??? when f(x) = x^2 - 4x - 9

OR

f(x+7) = x^2 - 4x - 9 , and you need to find f(x) ????

Answer 21

good point