Question 47656
0.2x + 0.4y = 1.7  and  8.3x - 6.3y = -4.3

Multiply thru both equations by 10 to get rid of the decimals:
1st: 2x+4y=17
2nd: 83x-63y=43
Multiply 1st by 83 to get:
3rd: 166x+332y=1411
Multiply 2nd by 2 to get:
4th: 166x-126y=86
Subtract 4th from 3rd to get:
458y=1325
y=2.893
Substitute into 1st or 2nd to solve for x:
2x+4(2.893)=17
2x=5.428
x=2.714
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Check the answer in 2nd, as follows:
83(2.714)-63(2.893)=43
43.003 = 43
The discrepancy is due to dropping values beyond the 3rd place.

Cheers,
Stan H.