Question

I have 7z - 3x = 18
2z = 1 + 5x

And now I dk what to do

Answer 1

ok thanks so much

Answer 2

x=1 and z=3

Answer 3

The is a literal equation with substitution I flipped the 2z = 1 + 5x

It was originally 2z - 5x = 1

Answer 4

it doesnt matter:)

Answer 5

divide by 2 to get z alone

Answer 6

I divide what by two?

Answer 7

2z = 1 + 5x
-----------; z = (1/2) +(5/2)x
2

Answer 8

What about the first equation?

Answer 9

what about it?

Answer 10

What happens to it

Answer 11

you sub the z value into it and solve for x

Answer 12

7z - 3x = 18

7((1/2)+(5/2)x) - 3x = 18

Answer 13

Then what do I do?

Answer 14

7((1/2)+(5/2)x) - 3x = 18 (2)

7(1+5x) - 6x = 36

Answer 15

7+35x -6x = 36

x = 1

Answer 16

Ugh. Now I should have known that!

Answer 17

i goofed that answer but you see it lol

Answer 18

What about the 7?

Answer 19

Doesn't it get multiplied by 2 also?

Answer 20

7+35x -6x = 36

29x = 29 ..... x=1; lol thats a coincidents

Answer 21

lets focus on that part and see what I did ok?

Answer 22

1+5x
7( ----- ) times 2 = 7(1+5x)
2

Answer 23

How do I find the Y again?

Answer 24

Because I am confused about that bit right know?

Answer 25

the y or the z?

Answer 26

Sorry, Z

Answer 27

ok... do you see why when we mulitply by 2 we get 7(1+5x) tho?

Answer 28

Yes

Answer 29

then lets solve for x:

7+35x -6x = 36 ; -7 and add like terms

7-7+35x -6x = 36-7

29x = 29

x = 1 right?

Answer 30

Yes I have the much of the problem solved :D

Answer 31

2z = 1 + 5x

2z = 1+5

2z = 6

z = 3

Answer 32

Finally the problem is finished :D

Answer 33

once you know what x is....use it lol

Answer 34

Thks again!!!!!!!!!!!!!!

Answer 35

yw :)

Answer 36

The problem looks like this

7z - 3x = 18
2z - 5x = 1 changes to 2z = 1 + 5x

Then I divide 2z by 2 to get

7z - 3x = 18
z = 1/2 5x/2

which turns to

7(1/2) 5x/2) - 3x = 18 which turns to 7 + 35x -6x = 36 which turns to 7 + 29x = 36 which turns to 29x = 29 then x = 1

then

2z = 1 + 5 (1)
2z = 1 + 5
2z = 6
z = 3

(1,3)