How many solutions does the following system have?

2x + 3y = 1; - 3x - 2y = - 1

1 answer

To find the number of solutions for this system of equations, we can solve the equations simultaneously to see if there is a unique solution, no solution, or infinitely many solutions.

We can use the method of elimination to solve this system. First, let's multiply the second equation by 2 to eliminate the y-term:

-3x - 2y = -1
2(-3x - 2y) = 2(-1)
-6x - 4y = -2

Now, let's add this equation to the first equation:

2x + 3y = 1
+ (-6x - 4y = -2)
-----------------
-4x - y = -1

Now, we have a system of two equations:

-4x - y = -1
2x + 3y = 1

To eliminate the y-term this time, let's multiply the first equation by 3 and the second equation by 4:

3(-4x - y = -1)
4(2x + 3y = 1)

This gives us:

-12x - 3y = -3
8x + 12y = 4

Now, let's add these two equations:

-12x - 3y = -3
+ (8x + 12y = 4)
----------------
-4x + 9y = 1

We now have a system of two equations:

-4x + 9y = 1
2x + 3y = 1

We can eliminate the x-term by multiplying the first equation by 2 and the second equation by -4:

2(-4x + 9y = 1)
-4(2x + 3y = 1)

This gives us:

-8x + 18y = 2
-8x - 12y = -4

Now, let's add these two equations:

-8x + 18y = 2
+ (-8x - 12y = -4)
------------------
0x + 6y = -2

Simplifying this equation gives us:

6y = -2
y = -2/6
y = -1/3

Now, let's substitute this value of y back into one of the original equations, such as the first equation:

2x + 3y = 1
2x + 3(-1/3) = 1
2x - 1 = 1
2x = 2
x = 1

Therefore, the solution to the system of equations is x = 1 and y = -1/3.

Since we found a unique solution (x = 1, y = -1/3), the system of equations has only one solution.