Answer:
Option C: x=3 and y= -6 is the correct answer.
Step-by-step explanation:
Given that:
x - 2y = 15 Eqn 1
2x+4y = -18 Eqn 2
Multiplying Eqn 1 by 2
2(x-2y=15)
2x-4y=30 Eqn 3
Adding Eqn 2 and Eqn 3,
(2x+4y)+(2x-4y)=-18+30
2x+4y+2x-4y=12
4x=12
Dividing both sides by 4
[tex]\frac{4x}{4}=\frac{12}{4}\\x=3[/tex]
Putting x=3 in Eqn 2
2(3)+4y=-18
6+4y=-18
4y= -18-6
4y= -24
Dividing both sides by 4
[tex]\frac{4y}{4}=\frac{-24}{4}\\y=-6[/tex]
Hence,
Option C: x=3 and y= -6 is the correct answer.