Question 71865
<pre>Please help thanks!

My homework question is choose the inequality that is equivalent to x > -9

Please show me how to find out what the answer is?

(a) 5x>45    (b) -5x < 45    (c) -5x > -45   (d) -5x < -45

------------------------------------------------------------
<font size = 4><b>
Solve each one and see.  I know that the answer is (b) so let's solve
all the others first, and (b) last, so you'll see why the others are
incorrect:

(a) 5x > 45    

Divide both sides by 5

     x > 9

No that's not x > -9

----------------------------

(c) -5x > -45

Divide both sides by -5. Here you MUST remember that
when you divide both sides of an inequality by a negative
number, the symbol of inequality must be reversed.

     x < 9

No that's not x > -9

----------------------------

(d) -5x < -45

Again, divide both sides by -5. Here we also remember that
when you divide both sides of an inequality by a negative
number, the symbol of inequality must be reversed.

       x > 9

No that's not x > -9

-----------------------------

(b) -5x < 45

Again, divide both sides by -5. Here we also remember that
when you divide both sides of an inequality by a negative
number, the symbol of inequality must be reversed.

       x > -9

Yes, that's it!

Edwin</pre>