Question

Match the answers up?

Questions:
5k^2+4k-1
2k^2-5k-3
3k^2+2k-5
7k^2-13k-2
10k^2-3k-1
Answers:
(7k+1)(k-2)
(2k+1)(k-3)
(3k+5)(k-1)
(5k-1)(k+1)
(2k-1)(5k+1)

Answer 1

Its just factoring by splitting the middle term. Hope you know how to do that?

Answer 2

I wasn't there the week my teacher was teaching it...

Answer 3

OK, lets take an example:
5x^2 + 4k - 1

Answer 4

Sorry, 5k^2

Answer 5

Ok.

Answer 6

Now, multiply the constants of the first and last term.

Answer 7

Grab a calculator that does polynomial equations with power 2 and insert the numbers one by one.

Answer 8

5 or 10?

Answer 9

And sevag, that isn't going to help in understanding how to do the sum.

Answer 10

I'm just kidding.

Answer 11

Multiply 5 and -1

Answer 12

-5

Answer 13

Which is -5. Understood till here?

Answer 14

The middle term is 4. Now find two numbers whose sum is 4 and product is -5.

Answer 15

Its easy though. Use the answers and multiply together like the (7k+1)(k-2). As you're multiplying you see that this is 7k^2-13K-2.

Answer 16

If its a big number, keep on finding the factors and keep adding them. In this case its easy:
5 * -1 = -5
5 + -1 = 4

Answer 17

You're right sevag, but it'll be tough if you don't have options.

Answer 18

Did you understand my last post?

Answer 19

Yeah i know that. But the questions is match the answers up. That's why i said multiply.

Answer 20

The worksheet came with a riddle and I figured it out before I got the answers and just paired them with eachother...

Answer 21

OK, so now its very simple. Split the middle term(4k) into 5k and -1k(which is the same as -k):
5k^2 + 5k - k - 1
= 5k(k + 1) - 1(k + 1)
= (5k - 1)(k + 1)
Hope you can solve the rest of the sums on your own now.

Answer 22

Ok, thanks.