Sophia.13
Solve using two differemt methods. Explain which method you found to be more efficient.
a. 3x-9y=3
6x - 3y= -24
Delete
Share
This Question is Closed
wio
Best Response
You've already chosen the best response.
1
The two methods are elimination and substitution.
Sophia.13
Best Response
You've already chosen the best response.
0
There is also graphing
skullpatrol
Best Response
You've already chosen the best response.
0
What have you tried?
Sophia.13
Best Response
You've already chosen the best response.
0
Nothing yet, i know how to do elimination. But i dont know how to substitution or graphing.
skullpatrol
Best Response
You've already chosen the best response.
0
Use elimination and find the answer first. All the methods should give the same answer, right?
Sophia.13
Best Response
You've already chosen the best response.
0
Ok
skullpatrol
Best Response
You've already chosen the best response.
0
$$ 3x-9y=3$$
$$ 6x - 3y= -24$$
Sophia.13
Best Response
You've already chosen the best response.
0
I got 3x-6y= -27 but i dont think its rigth is it?
skullpatrol
Best Response
You've already chosen the best response.
0
No.
Sophia.13
Best Response
You've already chosen the best response.
0
oh
Sophia.13
Best Response
You've already chosen the best response.
0
well, how do i do it?
Azteck
Best Response
You've already chosen the best response.
1
Do it simultaneously.
skullpatrol
Best Response
You've already chosen the best response.
0
You said you know how to use elimination. Try multiplying the first equation by $$-2$$ and add it to the second equation...
skullpatrol
Best Response
You've already chosen the best response.
0
$$ (3x-9y=3) (-2)$$
6x - 3y= -24
Azteck
Best Response
You've already chosen the best response.
1
\[3x-9y=3 [1]\]
\[6x - 3y= -24 [2]\]
\[2\times [1]\]
\[6x-18y=6 [3]\]
\[[2]-[3]\]
\[(6x - 3y) - (6x-18y)= (-24)-(6)\]
Azteck
Best Response
You've already chosen the best response.
1
\[-3y+18y=-30\]
The x's cancel out. Now you can solve for y. Once you solve for y, you can then substitute the y component that you just found, into any one of the equations above to find your x-value.
Azteck
Best Response
You've already chosen the best response.
1
If you need further assistance, I will be happy to elaborate it in more simple terms.