View Full Version : Help with this problem..
fabulous_lu
Jun 8, 2010, 07:35 AM
Okay,this is just one of the problems in my homework.. anybody who would like to help is much appreciated.. x+y=-4
x-y=2
This has to deal with the substitution method in Algebra 1.Again,all help is appreciated!
Unknown008
Jun 8, 2010, 09:24 AM
x + y = -4
x - y = 2
Actually, the elimination method would be the most direct method, but we'll use the substitution method :)
WE'll substitute the value of x into the first equation.
x - y = 2
Make x the subject of the formula;
x - y = 2
x - y + y = 2 + y
x = 2 + y
Now, use that in the first equation. Since x and y + 2 are the same, you can replace x by y + 2.
(y + 2) + y = -4
Now, I'm sure you can find the value of y. Then use this value to find the value of x.
Post your answer! :)
fabulous_lu
Jun 8, 2010, 07:12 PM
x + y = -4
x - y = 2
Actually, the elimination method would be the most direct method, but we'll use the substitution method :)
WE'll substitute the value of x into the first equation.
x - y = 2
Make x the subject of the formula;
x - y = 2
x - y + y = 2 + y
x = 2 + y
Now, use that in the first equation. Since x and y + 2 are the same, you can replace x by y + 2.
(y + 2) + y = -4
Now, I'm sure you can find the value of y. Then use this value to find the value of x.
Post your answer! :)
Okay thank you! :D
Unknown008
Jun 9, 2010, 06:41 AM
It'd be good that you post your answer too... but anyway, you're welcome :)