Question

what numbers do u multiply to get -30 but add to get 12 ???

Answer 1

\( \color{Black}{\Rightarrow ab = -30 }\)

\( \color{Black}{\Rightarrow a + b = 12 }\)

I think you are doing factoring

Answer 2

yes

Answer 3

I guess trial and error is better

Answer 4

You can solve this by substitution though

Answer 5

so what are the numbers?

Answer 6

Let's go with trial and error here. And logic.
One number has to be negative on the list because two negatives make a positive and two positives make a positive too.

Answer 7

right...

Answer 8

Also the number with the positive is much higher than the number with the negative.

Answer 9

okay..

Answer 10

-5 * 6 = 30
-3 * 10 = 30
-2 * 15 = 30

Answer 11

What's the expression btw?

Answer 12

yeah but none of those numbers add up to get 12

Answer 13

Can you tell me what trinomial is to be factored?

Answer 14

2x^2+12x-15

Answer 15

I think that the only way here is to complete the square.

Answer 16

http://www.wolframalpha.com/input/?i=2x%5E2%2B12x-15

Answer 17

okay thank you!

Answer 18

Yw!