Which of the following systems of equations has infinitely many solutions?
3x + 3y = 11; 6y = 6x − 22
8x − 7 = 6y; 12y − 14 = 4x
7y = x + 3; -3x + 21y = 9
5x − 7y = 4; 14y = 10x + 8

Question

Which of the following systems of equations has infinitely many solutions? 
   3x + 3y = 11; 6y = 6x − 22 
   8x − 7 = 6y; 12y − 14 = 4x 
   7y = x + 3; -3x + 21y = 9 
   5x − 7y = 4; 14y = 10x + 8

anonymous · Answer

@dpasingh can you help me with this please

anonymous · Answer

can you help me with the next one

anonymous · Answer

5x − 7y = 4; 14y = 10x + 8

anonymous · Answer

sure

anonymous · Answer

Solve using substitution:
2y − x + 2 = 0
-3x + 8y = -5
  (-10, 4)
   (3, 1/2) 
   (2, 0) 
   (4, 1)

anonymous · Answer

Ok wait!!

anonymous · Answer

ok

anonymous · Answer

2y − x + 2 = 0 i.e. 2y+2=x----1
-3x + 8y = -5-------2
substituting x= 2y+2 in eq 2 we find 
-3( 2y+2) +8y=-5
-6y-6+8y=-5
2y-6=-5
2y=6-5
2y=1
y=1/2
substituting y=1/2 in eq --1 we find
x= 2y+2=2(1/2)+2=1+2=3
Thus (x,y)=(3, 1/2) is the correct ordered pair