# algebra 2 question

• Sep 6th 2009, 09:29 PM
nike23
algebra 2 question
well this problem seems pretty long. can someone show me this step by step?

If f(x)= -4x²+2x-3, evaluate:

f(y+1) and 2f(5)

the first thing i did was get these:

-4(y+1)²+2(y+1)-3=??

2[-4(5)²+2(5)-3]=??

if i did something wrong, please tell me. and if not i would like to see how it is done. thanks.
• Sep 6th 2009, 09:41 PM
Chris L T521
Quote:

Originally Posted by nike23
well this problem seems pretty long. can someone show me this step by step?

If f(x)= -4x²+2x-3, evaluate:

f(y+1) and 2f(5)

the first thing i did was get these:

-4(y+1)²+2(y+1)-3=??

2[-4(5)²+2(5)-3]=??

if i did something wrong, please tell me. and if not i would like to see how it is done. thanks.

They're both set up properly. Now simplify them! :)
• Sep 7th 2009, 12:01 AM
mathsblog
Varify the same. all the best.

Quote:

Originally Posted by nike23
well this problem seems pretty long. can someone show me this step by step?

If f(x)= -4x²+2x-3, evaluate:

f(y+1) and 2f(5)

the first thing i did was get these:

-4(y+1)²+2(y+1)-3=??

2[-4(5)²+2(5)-3]=??

if i did something wrong, please tell me. and if not i would like to see how it is done. thanks.

• Sep 7th 2009, 07:07 PM
nike23
for the 2[-4(5)²+2(5)-3], i came up with -186.
and the first one, im not sure how i should evaluate it. the last thing i put was:
-4y²+6y+5, how much further should i go?
• Sep 8th 2009, 07:20 PM
Chris L T521
Quote:

Originally Posted by nike23
for the 2[-4(5)²+2(5)-3], i came up with -186.

(Yes)

Quote:

and the first one, im not sure how i should evaluate it. the last thing i put was:
-4y²+6y+5, how much further should i go?
I get \$\displaystyle -4y^2-6y-5\$...(Thinking)