Which pair of equations does NOT have a common solution?
A) x + y = -14x - 3y = 24
B) 4x + 6y = 12 6x + 9y = 12

C) 2x - 3y = -4 2x + y = 4

D) 5x - 4y = 9 x - 2y = -3

Question

Which pair of equations does NOT have a common solution?
A) x + y = -14x - 3y = 24	
B) 4x + 6y = 12 6x + 9y = 12

C) 2x - 3y = -4 2x + y = 4

D) 5x - 4y = 9  x - 2y = -3

anonymous · Answer

can somebody please help me..... ;P I'm having lots ah trouble with me.........

anonymous · Answer

B is the correct answer... BUT I GUESSSED. N i WOULD REALLY like to know why?? @TuringTest

anonymous · Answer

in b , multiply firs eq. by 3/2 u shoul get right hand side of the seconfd eq. as 18 but it is 12 so  no common soln.

anonymous · Answer

Didn't I show you how to do this before?
4x + 6y = 12
6x + 9y = 12

-3(4x + 6y = 12)
2(6x + 9y = 12)

-12x + -18y = -36
12x + 18y = 24

0 = -12
See? The variable disappeared and the numbers are different.

anonymous · Answer

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That's how the two lines look like. They're parallel.