Question

Use the elimination method to solve the system of equations. Choose the

correct ordered pair.
12x - y = 25
9x + y =17

Answer 1

The solution is: (2, -1)

Explanation:

I have the following system of equations

`12x - y = 25`

`9x + y =17`

Note that if we add both equations, the variable y is "eliminated".

So add the first equation to the second and solve for the variable x

`12x - y = 25`

`9x + y =17`

----------------------------------

`21x=42`

`x=(42)/(21)\\\\x=2`

Now substitute the value of x in any of the two equations and solve for the variable y

`9(2) + y =17`

`18 + y =17`

`y =17-18`

`y =-1`

The solution is: (2, -1)

Answer 2

the ordered pair is (2,-1)

Explanation:

We need to solve the system of equations using elimination method

12x - y = 25 eq(1)

9x + y = 17 eq(2)

Adding eq(1) and eq(2)

12x - y = 25

9x + y = 17

___________

21x = 42

x = 42/21

x= 2

Now, putting value of x in equation 1

12x - y = 25

12(2) -y = 25

24 -y = 25

Adding -24 on both sides

24 -y-24 = 25-24

-y = 25-24

-y = 1

Multiply both sides by -1

y = -1

the value of x = 2 and y = -1

So, the ordered pair is (2,-1)