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Question 71865: 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
Found 2 solutions by stanbon, Edwin McCravy:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! choose the inequality that is equivalent to X > -9
Please show me how to find out what the answer is?
Solve each possible answer for "x" to see which is x>-9
(a) 5x>45
Divide by 5 to get x>9; nope
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(B) -5x < 45
(Remember: dividing or multiply by a negative reverses the inequality.
Divide by -5 to get x>-9; that's the correct answer
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(c) -5x > -45
Divide by -5 to get x<9; nope
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(d) -5x < -45
Divide by -5 to get x>9; nope
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Cheers,
Stan H.
Answer by Edwin McCravy(20086)  (Show Source):
You can put this solution on YOUR website! 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
------------------------------------------------------------
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
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