factor x^2-9x+20

Question

factor x^2-9x+20

anonymous · Answer

(x-5)(x-4)

anonymous · Answer

can you explain

anonymous · Answer

Okay... well you're supposed to find two numbers, who multiply to 20 and add up to -9. 4 and 5 multiply to 20 and add to -9. So you write (x-4)(x-5)

anonymous · Answer

Daniel, do you understand what scientist explained?

anonymous · Answer

Factoring by using quadratic formula is always the best way rather than try to "optimize" by using random arithmetic. Understanding how the quadratic formula is obtained and why it works is the best next step.

anonymous · Answer

Yes, but it's up to level of the learners! To many, it's quite headache to solve just discriminant!

anonymous · Answer

this does give me a headache because I find it so hard to understand

anonymous · Answer

Watch the Khan video on quadratic formula. It will clear it up and give less headache.