Solve the system 3x – 2y = 7 and 9x – 6y = 3 by using graph paper or graphing technology. What is the solution to the system?

Question

anonymous · Answer

It doesn't have a solution 3(3x - 2y) = 3(7) => 9x - 6y = 21... Contradicts 9x - 6y = 3.  If you graph 9x - 6y and 3x - 2y, your lines will be parrallel.

To graph it and see for yourself.  Solve for y:
-2y = 3 - 3x ...
y = -(3/2) - -(3/2)x = (3/2)x - 3/2
or
-6y = 21 - 9x ...
y = -(7/2) - -(9/6)x = (3/2)x - 7/2

Notice they both have the same slope.  Only the intercept differs.