Question

solve
5x-2z=-5
9x+4z=16

Answer 1

If you double the first equation (mult everything by 2) and add the two equations, you get

19x = 6.

Can you get it from there?

Answer 2

Or did I lose you?

Answer 3

You would get x = 6/19 after dividing both sides by 19. Can you get z from this?

Answer 4

..... lost

Answer 5

One way to solve a system of two eq'ns and two unknowns is to add or subtract one equation to/from another. And it's always ok to multiply an equation by a number other than zero.

Answer 6

So if you start with your original equations, then multiply the first one by 2, you get:
10x-4z=-10
9x+4z=16.
And watch what happens when we add these ...

Answer 7

... we get
19x + 0z = 6
or just
19x = 6.

Answer 8

the original equation... Solve using elimination .
x-2y-4z=-10
2x+y+2z=5
3x-3y-2z=1 ?

Answer 9

I need to find x,y,z

Answer 10

That one is kind of a pain, but here's how to do it:
Solve the first equation for x:
x = -10 + 2y + 4z.

Next, replace the x in the other two equations by "-10 + 2y + 4z" ... you see where this goes?

Answer 11

Once you do this, you will be down to two equations and two unknowns (y and z). It's a bunch of steps, but each step is fairly straightforward.

Answer 12

Going back to your first problem, just remember to solve for z, too. The full solution would be (x,z) = (6/19, 125/38).

Answer 13

HHHHHUHUUUUUUUUUUUHHHHHH????

Answer 14

Sorry to have confused you. Which one are you confused about, the first problem or the second one?

Answer 15

use elimination method

Answer 16

Iknoooowwww I have to use the elimination method but im stuck ! ):

Answer 17

If you solve the first equation for x, you get x = -10 + 2y + 4z.

Now replace x in the other two equations with the value above. You get ...

Answer 18

... you get 2(-10+2y+4z) + y + 2z = 5

when you do this for the middle equation. Do you know how to simplify this?

Answer 19

-20 + 4y +8z + y + 2z = 5
-20 + 5y +10z = 5
+20 +20
5y+10z=25

Answer 20

Perfection!

Answer 21

Now you have to do the same thing to the third equation. A pain, right?

Answer 22

but how am i supposed to get them down into xyz form ? like no fraction or equations ?
??? S:

Answer 23

0,-3,4