Question

Someone expert please help.

I've encountered a quadratic equation and one part of it requires finding the range of x

(4-y)(y+5)>=0

I've found out the ranges by contradiction but can't seem to understand -5 12 years ago

Answer 1

Sorry range of y

Answer 2

Think about what happens in each region. Suppose y<-5

then (4-y)> 0 (can u see why?) and (y+5)<0

so what does that tell us about (4-y)(y+5)? ie we have a positive number times a negative number, what will that give us?

Similarly, if y>4 we get a negative number also

so we can conclude that y>-5 and y<4

hence -5<y<4

Answer 3

Does that help?

Answer 4

You're just great. Are you in some university or something?

Answer 5

Yes, I am a college student lol

Answer 6

Instant fan! :)

Answer 7

You guys have great education there.. Sigh I wish I'd get atleast 25% scholarship to study in the states.

Answer 8

I'm not from the states, I'm from the Caribbean, but I definitely understand what you mean, I feel the same way about my college.

The good thing about math is that you can do alot of it on your own if you like it

Also, never count yourself out, do your best and you may just get one

Answer 9

Still a year left till college- But thanks anyway