Question

I need some help solving for the variable, can someone help? also show me how please?

8x+2y=−12
5x−y=4.

Answer 1

Answer:

(-2/9, -46/9)

Step-by-step explanation:

I assume you want to solve the system of equations?  There are two ways you can do this: substitution and elimination.

Let's try substitution first.  Solving for y in the second equation is easy, so let's start there.

5x − y = 4

5x = 4 + y

5x − 4 = y

Now substitute this into the first equation:

8x + 2y = -12

8x + 2(5x − 4) = -12

8x + 10x − 8 = -12

18x = -4

x = -2/9

y = 5x − 4

y = 5(-2/9) − 4

y = -10/9 − 4

y = -10/9 − 36/9

y = -46/9

That's one way.  Now let's try using elimination.  Double the second equation:

2(5x − y) = 2(4)

10x − 2y = 8

Now add to the first equation:

(8x + 2y) + (10x − 2y) = -12 + 8

18x = -4

x = -2/9

Plug into any equation to find y.

5x − y = 4

5(-2/9) − y = 4

-10/9 − y = 4

-10/9 − 4 = y

y = -46/9