Question

Check me, please?

solve by factoring: x^2-5x-36=0

Using the sign of the constant term, determine whether your two factors will have (choose one):

A) 2 positive numbers

B) Two negative numbers

C) One positive number and one negative number

I think it's A.

Answer 1

the constant term -36 , is the product of the two numbers, the sign is negative so the signs of the two numbers must be ......

Answer 2

negative? So it'd be B? @UnkleRhaukus

Answer 3

a negative number times a negative number equals a positive number

Answer 4

but you are looking for a combination that produces a negative number

Answer 5

So it'd be C) a positive number and a negative number? @UnkleRhaukus

Answer 6

Yes, C is correct now why exactly is it correct @hpforever ?

Answer 7

because a positive number times a negative number equals a negative and negative 36, the constant, is a negative number? @MathLegend

Answer 8

So your post: "because a positive number times a negative number equals a negative" now isn't also true that we chose a positive and a negative number because the second term is negative? By any chance do you know what this actually factors out to be? @hpforever I want to take this a step further to see if you have a true understanding.

Answer 9

Factoring it out, I get (x+4) (x-9) @MathLegend

Answer 10

Good job! @hpforever

Answer 11

Great work!

Answer 12

Thank you both!! @UnkleRhaukus @MathLegend