# algebra

posted by on .

confrused with this one too let f(x)=x^2+6 and g (x) =4x-5 find (f ° g)(-7)

• algebra - ,

just plod along

first do g(-7)

then do f(whatever you got for g)

• algebra - ,

i got -55/7 is that right?

• algebra - ,

g(-7) = 4(-7) - 5 = -28 - 5 = -33

f(-33) = (-33)^2 + 6 = 1095 ???

• algebra - ,

according to my multiple choices its a fraction a -55/7 b 384/7 c 295/49 d 63/55

• algebra - ,

Then there is a typo somewhere. There was no divide in the problem statement. Perhaps at x = -1/7 ??

• algebra - ,

f(x)=x^2+6 and g (x) =x +8/xfind (f ° g)(-7) yep there was sorry

• algebra - ,

are you absolutely sure g(x) is not (x+8)/x ??

• algebra - ,

if g(x) = (x+8)/x
then
g(-7) = -1/7
then
f(-1/7) = 1/49 + 6
= 1/49 + 294/49
= 295/49

• algebra - ,

BUT
if it is as you wrote it

f(x)=x^2+6 and g (x) =x +8/xfind (f ° g)(-7) yep there was sorry

then
g(-7) = -7 + 8/-7
= -49/7 - 8/7=
= -57/7
the f(-57/7) = 57^2/49 +294/49
=3249/49 + 294/49
= 3543/49
which is not even on the list

• algebra - ,

ok then the other one is right im sorry and thank you

• algebra - ,

You are welcome