Question

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

4x - 2y = 6
2x + y = 5

A) -4x - 2y = 10
-4y = 4

B) -4x - 5y = -1
-7y = 5

C) 3x + 2y = 6
7x = 12

D) 4x + 2y = 10
8x = 16

Answer 1

4 x - 2 y = 6
2 x + y = 5 / * 2 ( we will multiply both sides by 2 )
-------------------
4 x - 2 y = 6
+
4 x + 2 y = 10
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8 x = 16; x = 2
4 + y = 5
y = 5 - 4; y = 1
In the system of equations D :
8 x = 16; x = 2 ,
8 + 2 y = 10
2 y = 2, y = 1
Answer: D ) is the equivalent system