Answer:
4 x minus 3 y = 16. 8 x minus 6 y = 34 has no solution
Explanation:
Examine the system
2 x + 8 y = 15
4 x + 16 y = 30
We see that these equations are identical except for a factor of 2, and thus recognize that this system has infinitely many solutions.
Next, look at the system
2 x minus y = 18
4 x + 2 y = 38
If we divide the second equation by 2, we get the system
2x - y = 18
2x + y = 19
Combining these two equations, we get 4x = 37, which has a solution.
Third, analyze the system
4 x + 7 y = 17 => 8x + 14y = 34
8 x minus 14 y = 36 => 8x - 14y = 36, or 16x = 70, which has a solution
Finally, analyze the system
4 x minus 3 y = 16 => -8x + 6y = -32
8 x minus 6 y = 34 => 8x - 6y = 34
If we combine these two equations, we get 0 + 0 = 2, which is, of course, impossible. This system has no solution.