Question

X-2y= 15

2x + 4y = -18
OA. x= 1, y= -6
OB. x= 1, y=-7
OC. x= 3, y= -6
D. x = 3, y=-7

Answer 1

Option C: x=3 and y= -6 is the correct answer.

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

`(4x)/(4)=(12)/(4)\\x=3`

Putting x=3 in Eqn 2

2(3)+4y=-18

6+4y=-18

4y= -18-6

4y= -24

Dividing both sides by 4

`(4y)/(4)=(-24)/(4)\\y=-6`

Hence,

Option C: x=3 and y= -6 is the correct answer.