Question

Solve by substitution:
x+3y=0
3x-6y=5

Answer 1

multiply the first equation straight across by 2, then add, the y terms will go bye bye

Answer 2

HI!!

Answer 3

ok so that would be 2x+6y=0

Answer 4

yes

Answer 5

then add in a column

Answer 6

Hi

Answer 7

Why do i need to add in a column?

Answer 8

if you do it you will see why

Answer 9

what @satellite73 said, the y terms will drop out because \(6y-6y=0\)

Answer 10

How do you add in a column....?

Answer 11

\[2x+6y=0\\
3x-6y=5\] andd and get \[5x=5\]

Answer 12

@satellite73 It said by substitution

Answer 13

there is more than one way to skin a cat

Answer 14

just do it this way lol

Answer 15

it should be clear what \(x\) is if \(5x=5\) right?

Answer 16

lol that saying though @satellite73

Answer 17

there are 4 methods used to solve simultaneous equations

Answer 18

x=1

Answer 19

yes

Answer 20

the directions specifically said to solve by substitution

Answer 21

then if \(x=1\) and \(x+3y=0\) that means
\[1+3y=0\] and you can solve that one for \(y\)

Answer 22

@triciaal what are we doing incorrectly?

Answer 23

"Solve by substitution:"
@ shelby1290 not following the directions

Answer 24

@shelby1290 the question said what method to use

Answer 25

bring 1 to the other side....
3y=0-1
3y=1
y=0.333333 lol

Answer 26

i would probably say \(-\frac{1}{3}\)
dont forget the minus sing

Answer 27

@triciaal I've checked my textbook and the answer is x=1 and y= -1/3

Answer 28

yeaaa

Answer 29

lol "sign"

Answer 30

whatever method you use will give the same answer

Answer 31

or the minus sing too, an nice tune

Answer 32

lol sign*

Answer 33

But thank you mistyyyy

Answer 34

*sigh...

Answer 35

\[\color\magenta\heartsuit\]

Answer 36

@shelby1290 as I said before there are 4 different methods that can be used to solve these equations

Answer 37

Yes I understand that.

Answer 38

the is the addition / elimination method where you eliminate one variable when you add the equations

Answer 39

Thank you for letting me know

Answer 40

to use the substitution method let one variable be the subject and use this expression for the variable in the second equation.

Answer 41

for example let x = -3y from the 1st equation then use this for x in the 2nd
3x - 6y = 5
3(-3y) -6y = 5
-15y = 5 so y = -1/3
use this value in the expression to get x
x = -3(-1/3) = -1

different method same answer (-1, -1/3)