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At which coordinate point do they intersect? X+y=-2 and y=4x+3

1 Answer

7 votes
Substitution Method

Step 1: Solve for either x or y in 1 of the 2 equations.

x + y = -2
- x - x
------------------------
y = -x - 2


Step 2: Plug in the expression you got for x or y into the opposite equation.

-x - 2 = 4x + 4
+ 2 + 2
-------------------------------
-x = 4x + 6
-4x - 4x
------------------------
-5x = 6
---- -----
-5 -5

x = -6/5


Step 3: Plug in the value for x or y into the equation you didn't use in Step 2.


-6/5 + y = -2
+ 6/5 + 6/5
--------------------------
y = -4/5


(x,y) = coordinate pair
(-6/5, -4/5) = final answer


User IvanRF
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