SOLUTION: I am really having hard time with linear equation systems and understanding how to solve them this problem is another one. 0.2x + 0.4y = 1.7 and 8.3x

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Question 230903: I am really having hard time with linear equation systems and understanding how to solve them this problem is another one.
0.2x + 0.4y = 1.7 and 8.3x - 6.3y = -4.3
Found 2 solutions by checkley77, unlockmath:
Answer by checkley77(12844) (Show Source):
You can put this solution on YOUR website!
0.2x + 0.4y = 1.7
.4Y=-.2X+1.7
Y=-.2X/.4+1.7/.4
Y=-.5X+4.25 (RED LINE)
8.3x - 6.3y = -4.3
-6.3Y=-8.3X-4.3
Y=-8.3X/-5.3-4.3/-6.3
Y=1.566X+.68254 (GREEN LINE)
(graph 300x200 pixels, x from -6 to 8, y from -6 to 8, of TWO functions -.5x +4.25 and 1.566x +.68254).
-------------------------
0.2x + 0.4y = 1.7 MULTIPLY THIS EQUATION BY 6.3.
8.3x - 6.3y = -4.3 MULTIPLY THIS EQUATION BY .4 & ADD THEM.
1.26X+2.52Y=10.71
3.32X+-2.52Y=-1.72
-----------------------
4.58X=8.99
X=8.99/4.58
X=1.963 ANS.
.2*1.963+.4Y=1.7
.3926+.4Y=1.7
.4Y=1.7-.3926
.4Y=1.3074
Y=1.0374/.4
Y=3.2685 ANS.
SOLUTION (1.963,3.2685)

Answer by unlockmath(1688) (Show Source):
You can put this solution on YOUR website!
Hello,
There's a couple ways to solve this or any system of equations. I'll show you one way and I'll try to keep it as simple as possible.
What we do is multiply the first equation by 15.75. You'll see in a second why we're doing this. This will give us:
(15.75)0.2x + (15.75)0.4y = (15.75)1.7 or
3.15x + 6.3y = 26.775
You'll see that 6.3y is now the same as in the other equation so we can add both equation together.
3.15x + 6.3y = 26.775
+ 8.3x - 6.3y = -4.3
This leaves us with 11.45x = 22.475

Divide 11.45 into both sides to give us:

x = 1.962882

(This number gets pretty strange so we need to ensure that you have copied exactly the correct numbers from the original problem in the book) Supposing you have copied the correct numbers; you would plug 1.962882 into the equation to find y.
Looks like this:
(0.2)(1.962882) + 0.4y = 1.7
Solve for y:
y = 1.3074236
You can put both the answers we got for x and y into either equation and it will be correct.
You might be wondering how I found 15.75 to multiply the first equation. I simply divided 6.3 by .4
RJ Toftness
Author of "Unlock the Mystery to Math"
www.math-unlock.com

SOLUTION: I am really having hard time with linear equation systems and understanding how to solve them this problem is another one. 0.2x + 0.4y = 1.7 and 8.3x - 6.3y = -4.3