Tuesday

September 16, 2014

September 16, 2014

Posted by **Crystal** on Tuesday, July 14, 2009 at 9:42am.

-.02x <= -70

x < = -70/-.02

x < = 3500

Or do the sign go the other way like this?

.04x + 720 - .06x > = 650

-.02x > = -70

x > = -70/-.02

x > = 3500

Which would be the solution to solve this inequality?

.04 x + .06(12000-x) >= 650

- Algebra -
**Reiny**, Tuesday, July 14, 2009 at 9:50amsee my final reply to

http://www.jiskha.com/display.cgi?id=1247546252

- Algebra -
**Crystal**, Tuesday, July 14, 2009 at 10:14amWhy is is greater than or = to? I got the answer as being < or = 3500? Can you please explain? Thanks!

- Algebra -
**Reiny**, Tuesday, July 14, 2009 at 10:24amYes, I had agreed that you were right,

and changed it to ≤

here is the corrected version

.04x + 720 - .06x ≥ 650

-.02x ≥ -70

x ≥ -70/-.02

x ≤ 3500

- Algebra -
**Crystal**, Tuesday, July 14, 2009 at 11:00amSo basically the > = stay the same for the first 2 lines and change to < = for the last? How does that work?

- Algebra -
**Reiny**, Tuesday, July 14, 2009 at 11:43amOk, I will illustrate with an example

e.g.

8 > 5 -----> True

if we add any number or subtract any number the statement is still true

8+6 > 5+6 ---> True

let's multiply by a positive number

8(4) > 5(4) -----> still True !

how about dividing by a positive

8/2 > 5/2 ??? Yes, still True

how about multiplying by a negative

8(-3) > 5(-3) or

-24 > -15 BUT THAT IS FALSE !!!

how do we make it true? We reverse the sign

-24 < -15 , now it's Truee

same thing for division by a negative.

So, in summary,

you can add/subtract any value just like for equations and the inequality sign stays the same.

Same is true for multiplying/dividing by a positive number.

BUT, when you multiply or divide by a negative number in an inequality, you have to reverse the inequality sign at that step. Usually this will be your last step.

- Algebra -
**Crystal**, Tuesday, July 14, 2009 at 12:06pmThank you! This is a great review of this topic! Thanks again!

**Answer this Question**

**Related Questions**

Algebra - Please solve the inequality .04 x + .06(12000-x) >= 650 .04x + 720...

ALGEBRA - for subtracting this problem: (0.04x^3-0.03x^2+0.02x)-(0.03x^3+0.08x^2...

math - I need help in solving this subtraction (0.06x^3-0.07x^2+0.04x)-(0.02x^3+...

bobpursly, check please,math - do you mean like this: 720/(V-30) + 720/(V+30) = ...

algebra homework check - The monthly rents for the apartments in a Business ...

pre-algebra - Solve the inequality- a/3>4 -2n<10 p/(-2)<-5 Trreat the ...

math - what is the rule for greater than less than sign. The greater than sign...

Math - How do you subract the fraction 2/5 and 4/9? Form a common denominator ...

homework check plz - The monthly rents for the apartments in a building are ...

PsyDAG homework check - The monthly rents for the apartments in a building are ...