Answer: (-3, -4)
Don't forget to enter the parenthesis surrounding the terms. Separate each coordinate with a comma.
======================================================
Step-by-step explanation:
The addition method is the same as the elimination method.
Add the equations straight down
- The x terms add to 2x
- The y terms add to 0 since y+(-y) = y-y = 0y = 0. Therefore the y terms go away, i.e. they've been eliminated.
- The right hand sides add to -7+1 = -6
We're left with 2x on the left side and -6 on the right side.
So we have 2x = -6 which solves to x = -3 after dividing both sides by 2.
Then use this to find y
x+y = -7
-3+y = -7
y = -7+3
y = -4
Or
x-y = 1
-3-y = 1
-y = 1+3
-y = 4
y = -4
We have x = -3 and y = -4 pair up together to form the solution (-3, -4)
Do not forget to type in the parenthesis and separate each item with a comma.
Visually we can use graphing tools to verify the answer. The two lines intersect at (-3, -4).
I used Desmos, but you could use GeoGebra or similar apps.