Question

Solve by Cross multiplication method x+2y+1=0 and 2x-3y-12=0

Answer 1

Answer:

x = 3

y = -2

Step-by-step explanation:

x + 2y + 1 = 0

2x - 3y - 12 = 0

Multiply first equation by -2.

-2x + -4y + -2 = 0

2x - 3y - 12 = 0

Add equations.

0x + -7y - 14 = 0

Solve for y.

-7y = 14

y =-2

Put y as -2 in the first equation and solve for x.

x+2(-2)+1=0

x + -4 + 1 = 0

x = 0 + 4 - 1

x = 3

Answer 2

Answer:

$\boxed{x = 3, y = -2}$

Step-by-step explanation:

$x+2y +1 = 0$

=> $x+2y = -1$ -------------------(1)

$2x-3y-12 = 0$

=> $2x-3y = 12$ -------------------(2)

Multiplying (1) by 2

=> $2(x+2y) = 2(-1)$

=> $2x+4y = -2$ ------------------(3)

Subtracting (3) from (2)

=> $2x-3y+2x-4y = 12+2$

=> -3y-4y = 14

=> -7y = 14

Dividing both sides by -7

=> y = -2

Now, Put y = -2 in Eq (1)

=> x+2(-2)+1 = 0

=> x -4+1 = 0

=> x - 3= 0

Adding 1 to both sides

=> x = 3