Posted by kgerlich@hotmail.com (24.67.211.104) on March 20, 2003 at 16:30:49:
In Reply to: The divided by marks posted by on March 20, 2003 at 03:06:30:
equation 1 is simplified to 1/2 (x+2y) = -y/4
The next step is x/2 = -y/4 + y
x = -5/2y
Now sub that in the second equation
y-x=7
y=x+7
y=-5/2y + 7
y=(-2.5)y+7
y+2.5y=7
3.5y=7
Now divide 7 by 3.5 and you get y=2
now put y=2 into the second equation
y-x=7
2-7=x
x=-5
therefore your solution is (-5,2)and your system is independent. Check your answer by putting x=-5 and y=2 into eqn 1.
(-5+2(2))/2 = (-1/4)(2)
-1/2 =-2/4
-0.5=-0.5
since left side = right side you know its done right. I hope that helped