SOLUTION: Help me solve this inequalities please...thanks Question 1: 2/3 < (x+5)/-4 < 3/2 2/3's is less than (x+5)/-4 is less than/equal to 3/2's. Question 2: 6x+5 4x-3 ---

Algebra ->  Inequalities -> SOLUTION: Help me solve this inequalities please...thanks Question 1: 2/3 < (x+5)/-4 < 3/2 2/3's is less than (x+5)/-4 is less than/equal to 3/2's. Question 2: 6x+5 4x-3 ---      Log On


   



Question 1762: Help me solve this inequalities please...thanks
Question 1:
2/3 < (x+5)/-4 < 3/2
2/3's is less than (x+5)/-4 is less than/equal to 3/2's.

Question 2:
6x+5 4x-3
---->----
-2 = 5
(6x+5)/2 is greater than/= to (4x-3)/5

Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
the thing with inequalities...they are JUST the same as equalities except for 1 important difference....if you multiply or divide by any negative number, then the inequality symbol changes round.
OK, assuming i have your questions correctly written, here are the solutions:
1. do the 2 inequalities separately, so...
a) %282%2F3%29+%3C+%28%28x%2B5%29%2F%28-4%29%29 first cross multiply, and note that one of the multiplications is a negative number, hence the inequality swaps round.
%28-4%29%282%29+%3E+%283%29%28x%2B5%29
-8+%3E+3x+%2B+15
-23+%3E+3x
3x+%3C+-23...this is EXACTLY the same line...no maths done here, i have just re-written the line with the x first, as that is "standard" notation.
x+%3C+%28-23%29%2F%283%29
b) %28%28x%2B5%29%2F%28-4%29%29+%3C=+%283%2F2%29
%282%29%28x%2B5%29+%3E=+%28-4%29%283%29 again, we have multiplied by a negative, so the inequality swaps over.
2x%2B10+%3E=+-12
2x+%3E=+-22
x+%3E=+-11
so, the answer is x has to be less than -23/3 which is -7%282%2F3%29. x also has to be bigger or equal to -11....so the answer in maths notation is...
-11+%3C=+x+%3C+%28-23%29%2F%283%29
=======================================================
2. %286x%2B5%29%2F%28-2%29+%3E+%284x-3%29%2F%285%29. Again we have a negative number to multiply with, so the symbol will change round...
%285%29%286x%2B5%29+%3C+%28-2%29%284x-3%29
%2830x%2B25%29+%3C+%28-8x%2B6%29
38x+%3C+-19
x+%3C+-%281%2F2%29
I hope this explains inequalities to you...they are very simple and you shouldn't be scared of them if you understand the basics of moving numbers around and multiplying out brackets etc.

cheers
Jon.