Determine the best method to solve the system of equations. Then solve the system.
5x+7y=-11
5x-3y=19
+9479 The fastest method looks like "elimination," where you line the equations up and add straight down.
5x + 7y = -11
5x - 3y = 19
If we added straight down right now, that would give us 10x + 4y = 8, which doesn't help any. We want one of the variables to go away.
Multiply the top equation by negative one all the way through.
(-1)(5x + 7y) = (-1)(-11)
-5x - 7y = 11
Now line up both equations and add straight down:
-5x - 7y = 11
5x - 3y = 19
0 - 10y = 30
-10y = 30
y = -3
Plug in y into either one of the equations to find x:
5x - 3(-3) = 19
5x + 9 = 19
5x = 10
x = 2
+9479 The fastest method looks like "elimination," where you line the equations up and add straight down.
5x + 7y = -11
5x - 3y = 19
If we added straight down right now, that would give us 10x + 4y = 8, which doesn't help any. We want one of the variables to go away.
Multiply the top equation by negative one all the way through.
(-1)(5x + 7y) = (-1)(-11)
-5x - 7y = 11
Now line up both equations and add straight down:
-5x - 7y = 11
5x - 3y = 19
0 - 10y = 30
-10y = 30
y = -3
Plug in y into either one of the equations to find x:
5x - 3(-3) = 19
5x + 9 = 19
5x = 10
x = 2
