SOLUTION: How do I apply elimination and substitution in solving a system of equations?
How do I demonstrate each technique in solving the system?
Lets use
3x+9y=12
5x-4y=3
I am
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-> SOLUTION: How do I apply elimination and substitution in solving a system of equations?
How do I demonstrate each technique in solving the system?
Lets use
3x+9y=12
5x-4y=3
I am
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Question 490314: How do I apply elimination and substitution in solving a system of equations?
How do I demonstrate each technique in solving the system?
Lets use
3x+9y=12
5x-4y=3
I am a Digital film and video production major and math is my weakness. Thank you in advance for your help. Found 2 solutions by Alan3354, MathLover1:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! 3x+9y=12 --> x + 3y = 4 after dividing by 3
5x-4y=3
------------
x + 3y = 4
5x- 4y = 3
-----------
To use elimination, get the coefficients of either x or y to match
Multiply the 1st eqn by 5:
5x +15y = 20
5x - 4y = 3
-------------- subtract
19y = 17
y = 17/19
------
then sub for y in any eqn and find x.
Even when you're asked to use elimination, only the 1st variable is found that way, then you substitute and find the others.
=========================================
Substitution: Solve either eqn for either variable in terms of the other.
It's easier to pick the one that has a coefficient of 1.
x + 3y = 4
5x- 4y = 3
--------
x + 3y = 4
x = -3y + 4
Sub for x in the other eqn.
5x - 4y = 3
5(-3y+4) - 4y = 3
-15y+20 -4y = 3
-19y = -17
y = 17/19 same answer
then sub for y in any eqn and find x.
You can put this solution on YOUR website!
you are given the system:
........1
........2
---------------------------..take one equation and solve it for one unknown variable (either or )
