SOLUTION: i need to use the substitution method to solve for this: x+4y=19 -4x+3y=38 i always mix up the substitution and elimination methods, what i got so far was -4(19-4y)+3y=

Algebra ->  Expressions-with-variables -> SOLUTION: i need to use the substitution method to solve for this: x+4y=19 -4x+3y=38 i always mix up the substitution and elimination methods, what i got so far was -4(19-4y)+3y=      Log On


   

Question 665544: i need to use the substitution method to solve for this:
x+4y=19
-4x+3y=38
i always mix up the substitution and elimination methods, what i got so far was
-4(19-4y)+3y=38
Found 2 solutions by Alan3354, lynnlo:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
i need to use the substitution method to solve for this:
x+4y=19
-4x+3y=38
i always mix up the substitution and elimination methods, what i got so far was
-4(19-4y)+3y=38
------------
That's one eqn in y, so it can be solved.
-4(19-4y)+3y=38
-76+16y + 3y = 38
19y = 114
y = 6
----------
x = 19-4y = 19-24
x = -5

Answer by lynnlo(4176) About Me  (Show Source):
You can put this solution on YOUR website!
EXAMPLE: YOU WILL THEN UNDERSTAND YOUR PROBLEMS BETTER
2X+3Y=5
X+Y=5
STEP(1)=======SOLVE ONE OF THE EQUATIONS X= OR Y=
I SOLVED THE SECOND EQUATION
X+Y=5
Y=5-X
STEP(2)=======SUBSTITUTE THE SOLUTION IN STEP 1 INTO THE SECOND EQUATION
2X+3Y=5
2X+3(5-X)=5
STEP(3)=======SOLVE EQUATION
2X+3(5-X)=5
2X+15-3X=5
-X+15=5
-X=5-15
X=10
STEP(4)===========
SOLVE THE FIRST VARIABLE
Y=5-X
Y=5-10
Y=-5
X=10,Y=-5
I HOPE THIS EXAMPLE REALLY HELP WITH YOUR WORK