Ask your own question, for FREE!
Mathematics 26 Online
OpenStudy (anonymous):

Please help! I have a complicated word problem.

OpenStudy (anonymous):

In a certain town, the inches of rainfall, x, on a certain day is described by two statements: If 3 times the rainfall is increased by 2, the rainfall is still less than 26 inches. 5 plus twice the rainfall is greater than 11 inches. Part A: Create a compound inequality to represent the rainfall range. (3 points) Part B: Can the rainfall in this town be 4 inches? Justify your answer by solving the inequalities in Part A. (3 points) Part C: The average rainfall in another town is 5 inches but the actual rainfall is within 4 inches of the average. Write and solve an inequality to find the range of rainfall height in this town. (4 points)

OpenStudy (ash2326):

We know that rainfall on that particular day is x inches. Let's try to create inequality for the first statement: If 3 times the rainfall is increased by 2, the rainfall is still less than 26 inches. Can you try?

OpenStudy (ash2326):

@micahpkay ???

OpenStudy (anonymous):

Sorry about that. I accidentally exited my window with a bunch of tabs open and it took forever to load again.

OpenStudy (anonymous):

3x + 2 < 26

hartnn (hartnn):

yes, correct :) now how about 5 plus twice the rainfall is greater than 11 inches. ?

OpenStudy (anonymous):

2x + 5 > 11

OpenStudy (anonymous):

But what do I do with these expressions?

hartnn (hartnn):

good. could you solve them ?

hartnn (hartnn):

those are inequalities, you can isolate 'x' from each of them

OpenStudy (anonymous):

*equations

OpenStudy (anonymous):

3x + 2 - 2 < 26 - 2 3x < 24 3x/3 < 24/3 x < 8

OpenStudy (anonymous):

2x + 5 > 11 2x + 5 - 5 > 11 - 5 2x > 6 2x/2 > 6/2 x > 3

OpenStudy (anonymous):

Correct?

hartnn (hartnn):

yes! so x can take any value which is >3 and less than 8 so, can x take the value of 4 ?

OpenStudy (anonymous):

Yes.

OpenStudy (anonymous):

Would I write it as 3 < x < 8?

hartnn (hartnn):

yes,

OpenStudy (anonymous):

So is "3 < x < 8?" the answer to Part A?

hartnn (hartnn):

yes, yes it is!

OpenStudy (anonymous):

Sorry about leaving. Are you still there?

hartnn (hartnn):

yes

OpenStudy (anonymous):

Okay.

OpenStudy (anonymous):

Can you help me on Part C?

hartnn (hartnn):

actual rainfall is within 4 inches of the average (=5) so, let the actual rainfall be 'x' x is not more than 4 inches greater than 5 or x is not less than 4 inches lesser than 5 can you try to make an equality ?

hartnn (hartnn):

no... 5 is avg. and x can be only 4 inches far from 5 so, x-4 < 5 or x+4 >5

OpenStudy (anonymous):

So do I simplify these inequalities?

hartnn (hartnn):

yes, and then you can prepare a compound inequality from it :)

OpenStudy (anonymous):

x - 4 < 5 x - 4 + 4 < 5 + 4 x < 9

hartnn (hartnn):

yes

OpenStudy (anonymous):

x + 4 > 5 x + 4 - 4 > 5 - 4 x > 1

hartnn (hartnn):

yes

OpenStudy (anonymous):

So now what?

hartnn (hartnn):

x> 9 or x<1 try to combine this ?

OpenStudy (anonymous):

9 < x < 1

OpenStudy (anonymous):

How is that even possible??

hartnn (hartnn):

oh wait, its x<9 not x>9 that you found so, combine x<9 and x>1

OpenStudy (anonymous):

Yeah. That's what I thought. lol

OpenStudy (anonymous):

1 < x < 9

hartnn (hartnn):

yes, it is :)

OpenStudy (anonymous):

Okay thanks. :) PS: I found x < 9, not x > 9.

hartnn (hartnn):

yeah, yes.

OpenStudy (anonymous):

The instructions say to write AND solve the inequality. How do I "solve" it?

hartnn (hartnn):

you already solved it, solve means to isolate x write the inequality : x-4 < 5 or x+4 >5 solve it : ..... 1 < x < 9

OpenStudy (anonymous):

Oh, okay.

OpenStudy (anonymous):

Thanks for helping me! You deserve 10 medals! lol

OpenStudy (anonymous):

:)

hartnn (hartnn):

you're most welcome ^_^ you understood it, thats my medal :)

OpenStudy (anonymous):

How sweet. I'm crying. jk :)

OpenStudy (anonymous):

It's 5:00 in the morning where I live. Time for bed. lol

hartnn (hartnn):

ohh! have a good night and sweet dreams :)

OpenStudy (anonymous):

You too. Cya!

OpenStudy (anonymous):

Final Answer Part A: 3x + 2 < 26 3x + 2 - 2 < 26 - 2 3x < 24 3x/3 < 24/3 x < 8 _____ 2x + 5 > 11 2x + 5 - 5 > 11 - 5 2x > 6 2x/2 > 6/2 x > 3 _____ If "x" is greater than 3 but less than 8, I can write the compound inequality shown below. 3 < x < 8 Part B: Yes, it can be 4 inches because 4 is greater than 3 and less than 8. I already solved the inequalities in Part A. Part C: x - 4 < 5 or x + 4 > 5 _________________________ x - 4 < 5 x - 4 + 4 < 5 + 4 x < 9 _____ x + 4 > 5 x + 4 - 4 > 5 - 4 x > 1 _____ Since "x" is greater than 1 but less than 9, I can write the compound inequality shown below. 1 < x < 9

hartnn (hartnn):

seems good :)

OpenStudy (anonymous):

Thanks.

OpenStudy (anonymous):

Okay. I'm going to bed now for sure. Bye!

hartnn (hartnn):

bye :) sleep tight.

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!