Question

19 + 2 x < 6 x + 20
Write answer in INTERVAL NOTATION.

Answer 1

I got no clue yo

Answer 2

@satellite73

Answer 3

Solve for x. Then you should get an inequality.

Answer 4

i got x>−1/4 but tats wrong

Answer 5

@theEric

Answer 6

That's what I have. The inequality is saying that x can equal anything that is greater than -1/4. So to write it in interval notation you use ( for values that x cannot equal.

Answer 7

how do i write it in interval notation
x>−1/4
like this (-1/4+oo)

Answer 8

\[19 + 2 x < 6 x + 20\\
19<4x+20\\
-1<4x\\
-\frac{1}{4}<x\]

Answer 9

\[(-\frac{1}{4},\infty)\]

Answer 10

x is greater than -1/4. So that means infinity amounts of number greater than -1/4.

You would write (-1/4,oo)

Answer 11

thanks for the help

Answer 12

No problem.

Answer 13

you guys are so helpful ;)

Answer 14

I don't think I saw anyone say exactly what I'm going to say, so I'll say it just in case!

The paren "(" or ")" is used on that side of the interval if that boundary number isn't included in your interval.

So, by saying \(\Large(\normalsize-\dfrac14, ...\) you say that \(-\dfrac14\) isn't part of your interval. That's correct, because \(x>-\dfrac14\), so \(x\) can't be \(-\dfrac14\). By the way, \(x\) just marks all the numbers that are accepted to be in the interval. I know you know that, but redundance can be good.

Answer 15

And you ALWAYS use the paren with infinity or negative infinity! Because, how can you include the number infinity? You really can't.. So, it's a paren.

Answer 16

Example:
\(\left(-\infty,\infty\right)\)