Question

Choose the equivalent system of linear equations that will produce the same solution as the one given below.

4x - y = -11
2x + 3y = 5

A) -4x - 9y = -19
-10y = -30

B) 4x + 3y = 5
2y = -6

C) 7x - 3y = -11
9x = -6

D) 12x - 3y = -33
14x = -28

Answer 1

4 x - y = - 11
2 x + 3 y = 5   / * ( - 2 )
----------------------
   4 x - y = - 11
- 4 x - 6 y = - 10
---------------------- 
        - 7 y = - 21
            y = 3
  4 x - 3 = - 11
  4 x = - 8
           x = - 2
  D ) 12 x - 3 y = - 33
        14 x = - 28
       -------------------
        x = - 2
        - 24 - 3 y = - 33
        - 3 y = - 33 + 24
        - 3 y = - 9
       y = 3
Answer:  The equivalent system is D ).