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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 :)