Question

What is the solution of the system of equations? Show all work.
3x+2y+z=7
5x+5y+4z=3
3x+2y+3z=1

Answer 1

@JakeV8 , forget the other one.. I need help with this one.

Answer 2

@satellite73 HELP ME!

Answer 3

@JakeV8 I need you.!

Answer 4

@A_Level_Student can you please help me?!

Answer 5

@baldymcgee6 can you PLease help me?! I'm desperate.. ):

Answer 6

@jim_thompson5910 please help me! ):

Answer 7

what method(s) are you allowed to use? if any, which methods are you familiar with?

Answer 8

Substitution graphinf elimination ect.. And I just need someone to take me through it step by step, I've been working on this homework for 6 hours....

Answer 9

Substitution may be easiest...graphing is most likely impossible (unless you have a 3D graphing calculator with you)

Answer 10

What do you get when you solve

3x+2y+z=7

for z ??

Answer 11

idk... i kept getting like ridiculous negative decimals.....

Answer 12

Subtract 3x from both sides

3x+2y+z=7

2y+z=7-3x

Then subtract 2y from both sides

2y+z=7-3x

z=7-3x-2y

Then optionally, rearrange the terms

z=7-3x-2y

z=-3x-2y+7

So after solving 3x+2y+z=7 for z, we get z=-3x-2y+7

Answer 13

With this, we can replace each 'z' in the other two equations with -3x-2y+7 to get


Plug in z=-3x-2y+7 into the second equation

5x+5y+4z=3

5x+5y+4(-3x-2y+7)=3

5x+5y-12x-8y+28=3

-7x-3y+28=3

-7x-3y=3-28

-7x-3y=-25

So after replacing 'z' with -3x-2y+7 in the second equation 5x+5y+4z=3, we get -7x-3y=-25

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Then do the same for third equation

3x+2y+3z=1

3x+2y+3(-3x-2y+7)=1

3x+2y-9x-6y+21=1

-6x-4y+21=1

-6x-4y=1-21

-6x-4y=-20


So after replacing 'z' with -3x-2y+7 in the third equation 3x+2y+3z=1, we get -6x-4y=-20

Answer 14

This is a lot, but we come away with the new system of equations


-7x-3y=-25
-6x-4y=-20


You can use any method you want to solve this new system of equations to find x and y.

Answer 15

is it 4,-3