Question 1134451
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<pre>
(a)  An equation ax + by = c has the slope  m = {{{-a/b}}}. 

     Therefore, the slope is positive if and only if  {{{-a/b}}} > 0.



(b)  An equation ax + by = c has the slope  m = {{{-a/b}}}. 

     Therefore, the slope is negative if and only if  {{{-a/b}}} < 0.



(c)  An equation ax + by = c has the slope  m = {{{-a/b}}}. 

     Therefore, the slope is zero if and only if  a = 0,  b =/= 0.



(d)  An equation ax + by = c has the <U>indefinite</U> slope  

     if and only if  b = 0,  a =/= 0.
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I think I answered enough for one post.


To get the answers to other your questions (to the rest of your questions) - please re-post them.


The rule of this forum is &nbsp;<U>ONE &nbsp;AND &nbsp;ONLY &nbsp;ONE &nbsp;QUESTION</U> &nbsp;per post.


I understand that these questions go in block, &nbsp;so I answered to the entire block.


But please keep in mind that posting &nbsp;TOO &nbsp;MANY &nbsp;questions in one post is &nbsp;AGAINST &nbsp;the rules and is &nbsp;AGAINST &nbsp;of your best interests.




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<U>Comment from student</U>: Thank you. I didn't realize that the riddle I was given counted as multiple questions. Thank you for your time.
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<U>My responce</U>.  &nbsp;&nbsp;&nbsp;&nbsp;Excuse me.


This formula  &nbsp;"Thank you for your time." &nbsp;is used when I spent my time but not satisfied you / did not provide a solution.


But in &nbsp;<U>this case</U> &nbsp;I answered as much as I could and as much as it was possible in given situation.


In addition, &nbsp;I instructed you on how to manage your questions correctly in this forum.


So, &nbsp;the correct reaction in this case from your side would be to say me a full scale &nbsp;"Thanks for your solution/contribution" &nbsp;or, 
at least, &nbsp;simply "Thanks".



I forced to make this explanation because MANY visitors of this forum use the results of my work, but IGNORE ELEMENTARY RULES 
of courtesy behavior.