Question 1016728: -5a <= -25
Please have clear steps. Thank you so much! :D
Answer by FrankM(1040)   (Show Source):
You can put this solution on YOUR website! -5a <= -25
divide each side by 5
-a <= -5
Now, a side note, say -X>1. Can we just multiply both sides by -1 and get X>-1? In the first equation, -2 is a solution, as -(-2)>1 is true. But is -2>-1? No, sir, it's not. We must change equality sign when multiplying by a negative number.
a >= 5
This is the key to solving these, and for classmates getting this wrong on a test, the most common error. Now you won't make this mistake.
Last, it's the same if we just divided both sides by -5, multiply or dividing by a negative number forces an equality sign flip. Clear enough, I hope!
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