SOLUTION: Please help me with solving this problem by the addition method. 6x + 15y = -45 6x + 5y = -35 This is what I tried to do: 6x + 15y = -45 6x +

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Please help me with solving this problem by the addition method. 6x + 15y = -45 6x + 5y = -35 This is what I tried to do: 6x + 15y = -45 6x +       Log On


   

Question 256592: Please help me with solving this problem by the addition method.
6x + 15y = -45
6x + 5y = -35
This is what I tried to do: 6x + 15y = -45
6x + 5y = -35

12x + 20y =-75
Found 3 solutions by palanisamy, drk, richwmiller:
Answer by palanisamy(496) About Me  (Show Source):
You can put this solution on YOUR website!
The given equations are,
6x + 15y = -45 ...(1)
6x + 5y = -35 ...(2)
(1)-(2)=> 10y = -45+35
10y = -10
y = -10/10
y = -1
Substituting in (1), 6x-15 = -45
6x = -45+15
6x = -30
x = -30/6
x = -5
Therefore the solution is x = -5 and y = -1

Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
The method we will use is called the "elimination" or "multiplication-elimination" method. We want to get rid of a variable. Here was the original question:
(i) 6x+%2B+15y+=+-45
(ii) 6x+%2B+5y++=+-35
As we look at these equations, it would be easier to eliminate the variable. So, multiply (ii) by (-1) to get
(iii) -6x+-+5y+=+35
Now add (i) and (iii) to get
(iv) 10y+=+-10
solving for y, we get
y+=+-1
replace y with -1 into (i) to get
(v) 6x+%2B+15%2A%28-1%29+=+-45
solving for x, we get
6x+=+-30
x+=+-5
Our coordinate is (-5,-1)

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Here the addition method means subtract 6x+5y=-35 or add -(6x+5y=-35)
6x+15y=-45
6x+5y=-35
6x-6x=0
15y-5y=10y
-45-(-35)=-10
10y=-10
y=-1
plug 1 for y in either equation
6x+5y=-35
6x-5=-35
add 5
6x=-30
x=-5
(-5,-1)