Question

Solve the following system of equations

Answer 1

Answer:

$(x=3,y=-9)$

Step-by-step explanation:

The given systems is;

$1.2x + 2.4y = - 18 \\ - 0.8x + 0.4y = 6$

Divide the top equation by 1.2 and the bottom equation by by 0.8 to get:

$x + 2y = - 15 \\ - x + 0.5y = 7.5$

Now add both new equations:

$2y + 0.5y = 15 + - 7.5$

$2.5y = 7.5$

$x = \frac{7.5}{2.5} = 3$

Let us substitute x=3 into x+2y=-15 and solve for y.

3+2y=-15

2y=-15-3

2y=-18

y=-9

The solution is (x=3,y=-9)