If the quadratic equation x^2+10x-3 equals (x+a)^2-b, where a and b are integers, what is ab?
(x+5)^2-28
isn’t 28 considered a negative integer here? So, I did 5x(-28)= -140
I am confused when such questions are asked, and I don’t know whether I should take their signs into account.
Thank you.
Look at the form they want you to put it in: it’s (x - a)^2 - b. So if b = -28, (x - a)^2 - b \rightarrow (x - a)^2 - (-28) \rightarrow (x - a)^2 + 28.
If the form is (x - a)^2 + b, then b = -28 would work - can you see why?
I got it! Thank you
This is really tricky and confuses me all the time. What would you say is a neat trick for understanding the form they want you to put an answer in? Because I usually get in my head about this. Are there keywords that indicate that there’s a required form? Honestly thought I’d hacked it but I’ve clearly not.
The main “keyword” is the form you’re asked to put the expression in.
I’ll pay closer attention to this. Thank you