SOLUTION: Please help me with this substitution Method, I need the steps of how I would get to the answer: 2x-3y=-25 3x+y=1 Thank you for your help.

Algebra ->  Expressions-with-variables -> SOLUTION: Please help me with this substitution Method, I need the steps of how I would get to the answer: 2x-3y=-25 3x+y=1 Thank you for your help.      Log On


   



Question 283560: Please help me with this substitution Method, I need the steps of how I would get to the answer:
2x-3y=-25
3x+y=1
Thank you for your help.

Found 2 solutions by checkley77, JenniferTutors:
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
2x-3y=-25
3x+y=1
y=1-3x
Now replace y in the first equation with (1-3x) & solve for x.
2x-3(1-3x)=-25
2x-3+9x=-25
11x=-25+3
11x=-22
x=-22/11
x=-2 ans.
y=1-3*-2
y=1+6=7 ans.
Proof:
3*-2+7=1
-6+7=1
1=1

Answer by JenniferTutors(83) About Me  (Show Source):
You can put this solution on YOUR website!
To solve this problem by substitution method:
2x - 3y = -25
3x + y = 1
If you notice in the second equation, there is a y by itself (no number attached):
3x+%2B+y+=+1
First, subtract the 3x from the left to the right side of the equation:
y+=+-3x+%2B+1
Now place the y equals into the first equation:
2x+-+3y+=+-25
2x+-+3%28-3x+%2B+1%29+=+-25
Now follow order of operations:
Remember: Negative X Negative = Positive
2x+%2B+9x+-+3+=+-25
Now add like terms, x's:
11x+-+3+=+-25
To get 11x by itself, add the 3 from the left to the right side of the equation:
11x+=+-25+%2B+3
11x+=+-22
11x%2F11+=+-22%2F11
x+=+-2
Now you have the value of x, next place the x value into the first equation:
2%28-2%29+-+3y+=+-25
-4+-+3y+=+-25
Next add the 4 from the left to the right side of the equation:
-3y+=+-25+%2B+4
-3y+=+-21
Divide by negative 3 to get y by itself, Negative/Negative = Positive:
-3y%2F-3+=+-21%2F-3
y+=+7
Check both your values, x = -2, y = 7
Place it into either equation I placed it into the first,
2x+-+3y+=+-25
2%28-2%29+-+3%287%29=+-25
-4+-+21+=+-25
-25+=+-25