math problem?

Question

use elimination to solve each system of equations x+y=-4
4x+y=2
i need help step by step. thanx

Answer 1

x + y = -4.....(1)
4x + y = 2.....(2)

Subtract (2) from (1)
x - 4x + y - y = -4 - 2
-3x = -6
3x = 6
x = 2.....(3)

Substitute (3) in (2)
4x + y = 2
4*2 + y = 2
8 + y = 2
y = -6

The solution of this system of equations is x = 2, y = -6

Answer 2

To do this... what we have to do is eliminate one variable and then substitute it back into the equation and solve. Here are the steps

x + y = -4 and 4x + y = 2 first thing you want to do is determine which variable will be easy to eliminate. In our case y will be easy to eliminate. So we subtract the x + y = -4 from the second equation and we get
4x + y = 2
-(x + y = -4) which equals
-----------------------
4x + y = 2
-x - y = 4 add the two and we get
-----------------------
3x = 6 divide both sides by 3 to get
x = 2 Now that we have solved for x we can plug it back into one of the equations and solve for y. So let's plug it in x + y = -4 and we get
2 + y = -4 Now subtract 2 to both sides
y = -4 - 2
y = -6 so we get
x = 2 and y = -6or (2, -6) Final answer.

if you need further explanation or more help email me or im me. Good Luck.

Answer 3

okay elimination method requires you to eliminate one variable either 'x' or 'y' , solving for x if y is eliminated and vice versa. since both equations have a solo y value multiply the first one by -1(x+y= -4) giving us - x - y = +4 add the 2 together >>>>>>>>>>>>>>>>>>> + 4x +y= 2, -y and +y

cancel out leaving 3x=6, divide both sides by 3 giving you x=2, once you have the 'x' value sub it back in the top equation>>>>
(2) + y= -4 , subtract 2 from both sides giving you y= -6
there is your answer (x,y) or (2, -6)
P.S. this answer is where both graphs intersect or cross one another, also check by plugging x and y into one of the two formulas >>>>>>>> x+y= -4>>>> (2) + (-6) = -4 , -4 = -4 check is correct, 4x+y = 2>>>>>4(2) +(-6)= 2, 8+ -6 = -2
-2 = -2 checkmark
Hope this helps!!!!!!!!!!!!

Answer 4

Lets call x+y=-4 equation (1)
and call 4x+y=2 eqation (2)

If we subtract equation (1) from equation (2) the y terms will cancel, and we are left with:

3x=6 [remembering to subtract both sides of the equation from each other].

Dividing by three gives x=2

substituting this value for x into equation (1) means that y has to equal -6

Its always a good idea to substitute these values into the other equation to check your answer, and we see that subbing into equation (2) gives:

4*(2) +(-6) = 2 which is correct, therefore our values of x and y are correct.

Answer 5

Yeah, give the points to Tom :). However, if this is easier to read, use this:


(1) x + y = -4
(2) 4x + y = 2

Use substitution to modify (1) and (2):

(1) y = -4 - x
(2) y = 2 -4x

So now (1) and (2) are the same on the RHS (Right Hand Side), we can say (1) = (2):

-4 - x = 2 - 4x
3x = 6
x = 2

Now use either (1) or (2) to solve y:
(2) y = 2 - 4x
y = 2 - 8
y = -6

Done :)

Answer 6

the easiest way is probably just to mutuply everything inn x+y=-4 by a negative

-(x+y=-4) = -x-y=+4

Now you add this equation to 4x+y=2

-x-y=+4
+ 4x+y=2
_________
3x =6
x=2

now plug x in either -x-y=+4 or 4x+y=2

(-2) + -y= +4
+2 +2
-y=6
y= -6

or
4(2)+y=2
8 + y= 2
-8 -8
y=-6

final Answer

x=2 y=-6

Answer 7

x+y=-4
x=-4-y ----------------1
4x+y=2 ----------------2

subtituted 1 into 2

4(-4-y)+y=2
-16-4y+y=2
-3y=2+16
-3y=18
y=18/-3
y=-6

substituted y=-6 into 1
x=-4-y
x=-4-(-6)
x=-4+6
x=2

Answer 8

to solve this system by elimination method,
x+y=-4............................equ.1
4x+y= 2............................equ.2
equ.2-equ.1: -__-__-___________________
-3x= -6
x=-6/-3
x=2

substitute this value of x in equ.1
2+y=-4
y= -4-2
y= -6

Answer 9

- 4x - 4y = 16
4x + y = 2----------------ADD EQUATIONS
- 3y = 18
y = - 6
x - 6 = - 4
x = 2
Solution is x = 2, y= - 6

Answer 10

give the 10 pts. to Tom..