SOLUTION: Please help me solve this linear equation using substitution. 0.6x - 0.2y = -0.2 -0.03x - 0.07y = 0.17 Thank you.

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Please help me solve this linear equation using substitution. 0.6x - 0.2y = -0.2 -0.03x - 0.07y = 0.17 Thank you.      Log On


   



Question 702244: Please help me solve this linear equation using substitution.
0.6x - 0.2y = -0.2
-0.03x - 0.07y = 0.17
Thank you.

Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
This system,
0.6x - 0.2y = -0.2
-0.03x - 0.07y = 0.17
will be a bit more comfortable if you multiply the entire first equation by 10, and the entire second equation by -100.

You will then have the equivalent system,
6x-2y=-2
3x+7y=-17

Solve either equation for x OR y; substitute the found expression into the other equation and solve for the other variable. You now will have one of the values for that variable.

As example of a way to do the process, I pick the second equation and solve for y:
7y=-17-3x
y=(-17-3x)/7
Let me put this expression for y into the first equation.
6x-2(y)=-2
6x-2((-17-3x)/7)=-2
OR
6%2Ax-2%2A%28%28-17-3%2Ax%29%2F7%29=-2

Now solve for x,.....continue until done....!

... a little bit further into the process,
clear the fraction by multiplying both sides by 7:
42%2Ax-2%28-17-3%2Ax%29=-14
43%2Ax%2B34%2B6%2Ax=-14
48%2Ax=-34-14
48%2Ax=-48,
x=-1...... You can continue on from here...