t^2+6t-7. Is their a 2 numbers that equael product -7 and sum 6. Is it just me or thats not possible?

Question

t^2+6t-7.  Is their a 2 numbers that equael product -7 and sum 6. Is it just me or thats not possible?

kinggeorge · Answer

That's just you :)

There are indeed two numbers that multiply to be -7, and add to be 6. Think about it a bit and I'm sure you'll get it.

anonymous · Answer

Well the equation is set up as (a+1) (a-7) thats what I got. 
but 1-7=-6 so that doesnt work.

anonymous · Answer

remember that - and +  in front of the numbers

anonymous · Answer

Wrong way around mate

kinggeorge · Answer

That's very close.

anonymous · Answer

ok got it switched them. Now it works.

kinggeorge · Answer

Excellent!

anonymous · Answer

Thanks lol I cant believe i cudnt figure tthat out

kinggeorge · Answer

No problem. We've all had something obvious pass us by before :P

anonymous · Answer

would the solution set be written as (a+7) (a-1) or just {7,-1}

anonymous · Answer

are you factorizing? normally it wuold be written as full.

unklerhaukus · Answer

you could always use the quadratic formula 

$$t=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$

anonymous · Answer

(a+7)(a-1) that is....    you will need to use the full factors to use in equations.

kinggeorge · Answer

The solution set would be {-7,1}. Note that you have -7 and +1 because if $a+7=0$, then $a=-7$. Similarly, $a-1=0\implies a=1$.

anonymous · Answer

@Ben103  sorry the questions look like what I'm doing at school at the moment which is factorizing :( I could be wrong

anonymous · Answer

@KingGeorge knows more than me i'm sure! lol  I'm only doing high school maths

kinggeorge · Answer

As another tip, if you're asked for a solution SET, your final answer should look like {_,_,_,...,_}. I.e., you have a list of things in the curly brackets.

anonymous · Answer

Ok thanks I understand it now. :)

kinggeorge · Answer

You're welcome.