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Use the Substitution method to solve the system of equations.?
Use the Substitution method to solve the system of equations.
x + y = -4
x - y = 2
7 Answers
- 1 decade ago
Solve one of the equations for either x or y and substitute that into the second equation thereby eliminating one of the variables.
For example: 2nd equation could become x = y+2. Substituting this into the 1st eqn you get
(y +2) +y = -4 Solve this for y and you get y=-3
Therefore x = y+2 = -3+2 = -1
- 1 decade ago
Solve for one of the unknowns first.
x-y+y=2+y, simplified to x=y+2, since we know x equals y+2, we can replace "x" it in the first equation.
(y+2)+y=-4
simplified to:
2y + 2 = -4
subtract 2 from each side gives you:
2y = -6
Divide both sides by 2 gives you:
y = -3.
We can now subsitute y in either equation to solve for x.
x + (-3) = -4 , x = -1
We can test it in the other equation.
(-1) + (-3) = -4, which is true!
x = -1, y = -3
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- Anonymous1 decade ago
from (1) you have
x=-(4+y)
replace in (2)
-4-y-y=2
2y=-6
y=-3
x=-1
- Anonymous1 decade ago
Pshhhhh just graph it.