Asura.Tiran said: »
Been awhile since I've had to do these equations, but I'll try to explain it as best i can.
6x + 8y = 12
3x - 2y = -6
step 1: Identify the variable you wish to start with or eliminate first. I like to start with the first one in the equation, in this case 6x.
Step 2: In order to eliminate this variable (6x) you must use its opposite (-6x). To get this, you look at the second equation and identify what will make 3x change to -6x. In this case multiply by -2. You must apply the -2 to the whole equation. -2(3x- 2y = -6). Which results in -6x + 4y = 12
6x + 8y = 12
-6x + 4y = 12
Step 3: Eliminate the X variable by adding the equations together.
12y = 24 is the resulting equation.
Step 4: solve for Y
Y=2
Step 5: plug Y=2 back into the original equation. 6x + 8(2) = 12
Step 6: solve for X.
6x + 16 = 12 -> 6x = -4 -> x= -2/3
Hope this helps
6x + 8y = 12
3x - 2y = -6
step 1: Identify the variable you wish to start with or eliminate first. I like to start with the first one in the equation, in this case 6x.
Step 2: In order to eliminate this variable (6x) you must use its opposite (-6x). To get this, you look at the second equation and identify what will make 3x change to -6x. In this case multiply by -2. You must apply the -2 to the whole equation. -2(3x- 2y = -6). Which results in -6x + 4y = 12
6x + 8y = 12
-6x + 4y = 12
Step 3: Eliminate the X variable by adding the equations together.
12y = 24 is the resulting equation.
Step 4: solve for Y
Y=2
Step 5: plug Y=2 back into the original equation. 6x + 8(2) = 12
Step 6: solve for X.
6x + 16 = 12 -> 6x = -4 -> x= -2/3
Hope this helps
this, only you don't need to make the 2nd equation's variable the opposite (ei. 6x and -6x) they can be the same and subtract one equation from the other instead of adding. so
6x + 8y = 12
3x - 2y = -6
becomes
6x + 8y = 12
6x - 4y = -12
add subtract the 2nd equation from the first to get
12y = 24
and divide to get just y
y = 2
then to follow through with elimination and not substitution,
6x + 8y = 12
4(3x - 2y) = (-6)4
becomes
6x + 8y = 12
12x - 8y = -24
add them to eliminate y terms
18x = -12
and divide to get just x
x = -12/18 or x = -2/3
