Problem on Solving Equations by Elimination Method

Topic : Elimination Method

Problem : Solve 0.3x - 0.2y = 4 and 0.2x + 0.5y = -21/23 by elimination method

Solution :
0.3x - 0.2y = 4 ------------- (1)
0.2x + 0.5y = -21/23 ------- (2)

to make the coefficients of x equal, we multiply first equation by 0.2 and second equation by 0.3
0.3x - 0.2y = 4 X 0.2
0.2x + 0.5y = -21/23 X 0.3

 0.6x - 0.4y =  0.8
+0.6x + 1.5y = -0.274
-     -        +
______________________
     - 1.9y = 1.074

divide by -1.9 on both sides
So y = - 1.074/1.9
y = - 0.57
now we pulg in y = -0.57 in any equation. Lets take first one
0.3x - 0.2 (-0.57) = 4
0.3x + 0.114 = 4
subtract with 0.114 on both sides
0.3x = 4 -0.114
0.3x = 3.886
divide by 0.3
x = 12.95
So x = 12.95 and y = - 0.57