3x-4y=-24 and x+y=-1?

Question

solve by elimination please

Answer 1

x + y = -1
x = -1 -y & substitute into the other eq'n for 'x'.

3(-1-y) - 4y = -24
-3 -3y - 4y = -24
- 7y = -21
y = 3 & substitute into either eq'n to find 'x'

x + 3 = -1
x = -4

Answer 2

3x-4y=-24
x+y=-1
Multiply both sides of x+y=-1 by 4
3x-4y=-24
4x+4y=-4
-------------- Add
7x=-28
x=-4
Note that I added 4x+4y to the left side of 3x-4y=-24
to "eliminate" the y variable. I can do this, provided I add 4x+4y to the right side of 3x-4y=-24 as well. I did this! Since4x+4y=-4, I added the -4 instead.
Now, knowing x=-4, substitute -4 for x in either of the 2 original equations, to find y.
3x-4y+-24
3(-4)-4y=-24
-12-4y=-24
-4y = -24+12
-4y=-12
4y=12
y=3

Answer 3

3x-4y=-24
and
x+y=-1

Multiply second eqn by 3 to get
3x+3y=-3
Eliminate x by subtracting this from first eqn to get
-7y = -21
so y = 3 so x = -4
.

Answer 4

x=1-y substute for x in 3x-47 =24

3-3y-4y=24

-7y=21

y=-3

x=4

Answer 5

y = - 1 - x
3x - 4(- 1 - x) = - 24
3x + 4 + 4x = - 24
7x = - 28
x = - 4

y = - 1 - x
y = - 1 + 4
y = 3

x = - 4 , y = 3

Answer 6

multiply the second equation by 4
then add the equations 2gthr
get x
substitute that in2 either equation
and find y

Answer 7

3x - 4y = -24
1x + 1y = -1
-----------------


3x - 4y = - 24
-3x -3y = 3
-----------------
0 - 7y = -21

y = 3

x = -4