The choices are
A. p ≥ -5
B. p ≥ -17/3
C. p ≤ -17/3
D. p ≤ 5
The book says D, but I get p ≤ -5, which is not one of the answers. Why is my answer wrong, and what is the right way to solve this? It has to do with multiplying both sides of the inequality by a negative number, but I need the "Inequalities for Dummies" version. Thanks!
-3p + 1 ≥ 16 (I think the book is wrong.)?
2009-03-05 3:35 pm
回答 (7)
2009-03-05 3:41 pm
✔ 最佳答案
-3p + 1 ≥ 16-3p ≥ 15
for the sake of explanation, i'll divide by 3 and not -3 this time
-p ≥ 5
okay, think of it like this. the opposite (negative) of your number is greater than 5. so the number itself must be less than -5, so that when you multiply that number by -1 you get something > 5. therefore, you have to "flip the sign" when you divide by negative 1. in reality, you have to flip the sign every time you divide or multiply by a negative
so divide by your -1. and flip the sign around the other way!
p ≤ -5
not in the book, you're right
2009-03-05 3:49 pm
-5 x -3 = 15 + 1 = 16
-3(-5) + 1 = 16
The answer is A. Anything less than -5 will make the equation less than 16. The symbol in your equation is greater than or equal to.
-3(-5) + 1 = 16
The answer is A. Anything less than -5 will make the equation less than 16. The symbol in your equation is greater than or equal to.
2009-03-05 3:43 pm
Same here. The book is wrong.
2009-03-05 3:42 pm
-3p + 1 ≥ 16
-3p ≥ 16 - 1
-3p ≥ 15
p ≤ 15/-3
p ≤ -5
-3p ≥ 16 - 1
-3p ≥ 15
p ≤ 15/-3
p ≤ -5
2009-03-05 3:42 pm
damn your right the book is wrong and you are definitely right. nice i dont think anyone would have caught that mistake. call the company that makes the book and tell them they are wrong and you want your money back
2009-03-05 3:40 pm
D because when you devide by a negative the sighn switches
2009-03-05 3:39 pm
You're right. The book is in error.
D is probably supposed to show -5, but errors happen in math books too.
p ≤ -5 is the correct answer.
D is probably supposed to show -5, but errors happen in math books too.
p ≤ -5 is the correct answer.
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