2x - y + 3z = -6
-x + 2y - 3z = 12
y + 5z = -6

Solving the system of equations we get:

x=2, y=4, z=-2

Step-by-step explanation:

We need to solve the system of equations

Let:

First we find value of y from equation 3

Put value of y in equation 1

Now, put value of y in equation 2

Multiply equation 5 with 2 and add both equations 4 and 5

So, we get z=-2

Now put value of z in equation 3

So, we get y=4

Now, put value of y=4, and z=-2 in equation 1

So, solving the system of equations we get:

x=2, y=4, z=-2

x² + 3x + 7 = 0       [ax² + bx + c]

a = 1

b = 3

c = 7

quadratic formula:

    (+/- is this ±)

plug in the numbers into the variables

your answer is a