Answer:
and 
Step-by-step explanation:
To solve the system of equations with the linear combination method, you must:
- Arrange the equations in a colum.
- Make one of the set of terms, with equal variables, opposite in signs but equal in coefficients.
- Add both equations to cancel out that set of terms.
- Solve for the the variable left.
- Substitute the value of that variable into one of the original equations and solve for the other variable to find its value.
As you can see, the first equation of the system of equations given in the problem, does not have the variable
, so you can't apply the proccedure shown above. Then, to solve it you must:
-Solve for
in the first equation:

- Substitute the value obtained into the second equation and solve for
, then:

Therefore:
and 
The volume of a prism is given by its base area multiplied by its height.
The bases are two right triangles. If we project everything on the xy plane, we can see that the vertices of the base triangle is

So, leg AB is 3 units long, and leg AC is 4 units long. This means that the area of the triangle is

The height of the prism connects, for example, points
and
, so it's 5 units long. So, the volume of the prism is

Answer:
6 1/8 - 3 2/8 = 2 7/8
How I Found The Answer:
6 + 1/8 - 3 - 2/8
6 - 3 = 3
1/8 - 2/8 = -1/8
3 - 1/8 = 2 7/8