Question

sole the system of equations
x+y=5
3x+z=2
4y-z=8

Answer 1

does anyone know how to do this?

Answer 2

Eliminate the z variable to create a system of two equations.

Answer 3

ok so then what?

Answer 4

If you eliminated z, you should have:

x + y = 5
3x + 4y = 10

Now you have a system of two equations and two variables. You should be able to solve that.

Answer 5

so would that leave z to be 0 then?

Answer 6

Not necessarily. Solve the system of two equations first. You'll have values for x and y. From there, you'll be able to figure out the value of z

Answer 7

x=3 and y =2?

Answer 8

right?

Answer 9

@Hero

Answer 10

im completely stumped

Answer 11

I think you are guessing

\[3(3) + 4(2) \ne 10\]

Answer 12

If you cannot solve a system of two equations in two variables, then you should probably learn how to do that before attempting to solve systems of three variables.

Answer 13

that is why i come here for someone to explain how to solve a system of 2...

Answer 14

anyway of explaining it?

Answer 15

3x+4y=10 would i subtract 3 from both sides to find x?

Answer 16

No, that's not what you do, sorry bro.

Answer 17

then how do you do it?

Answer 18

Is this linear algebra?

Answer 19

no its pre cal

Answer 20

Okay then solve for one variable in terms of another.
x+y=5
3x+z=2
4y-z=8

solve for y in terms of x for
x+y=5
then solve for z in terms of x for
3x+z=2
then plug those values into
4y-z=8

Answer 21

Do you remember to solve equations? You add or multiply both sides of the equation to get only the variable you are solving for on one side

Answer 22

I'll do the first one
x+y=5
x-x+y=5-x ; subtract x from both sides
y=5-x ; now you have y in terms of x
now solve for z in terms of x for
3x+z=2