two ordered pairs for 2y=6x-2

Question

 must find two ordered pairs that are solutions to equation 2y=6x-2 

a.(7,22)(-2,-7)

b.(7,20)(-2,-7)

c.(7,22)(2,-5)

d.(7,20)(2,7)

Answer 1

With this type of a multiple choice question, you may either:

   (1) determine the correct answer(s) and then compare them to the distractors (the alternatives) to find the key(s) (the correct answers), or

   (2) use the values from each the distractors to determine whether they satisfy the conditions stated in the problem.

 

Now, method (1) is instructive, but often takes lots of time.  Method (2) may allow you to quickly eliminate obvious wrong answers and to quickly identify the key.  This helps when taking tests (especially the standardized ones because they are timed).

 

So, if x=7, as it in the first ordered pair of all the distractors, what is y?   y=(6x-2/2 = (42-2)/2 = 20.  The answer is either (b) or (d).  Now, you can take the time to plug in each x value to see if you get the associated y value.

Answer 2

 

 

Simply take seven, substitute it for x, and see what y becomes.  If it's y=22, then take -2, substitute it for x, and see what y becomes.  If that's y = -7, then you have shown that both the ordered pairs in choice a are on the line.

 

If a's values don't agree, repeat, using the x values given in b.  

 

All you have to do is test these calculations. Presumably answer will be one of a, b, c or d.