I would do this.
x+y = 9.0
0.50x + 0.20y = 3.90
------------------Multiply eqn 1 by -(1/2).
-0.50x - 0.50y = -4.50. keep eqn 2 as is.
0.50x + 0.20y = 3.90
-----------------------Now add the two. You see the x term cancels. Solve for y, then substitute y back into one of the equation and solve for x.
x+y=9.0
0.50x+0.20y=3.90
What is the value of x and y?
1 answer