Precalculus Examples
2x+y=-22x+y=−2 , x+2y=2x+2y=2
Step 1
Multiply each equation by the value that makes the coefficients of xx opposite.
2x+y=-22x+y=−2
(-2)⋅(x+2y)=(-2)(2)(−2)⋅(x+2y)=(−2)(2)
Step 2
Step 2.1
Simplify the left side.
Step 2.1.1
Simplify (-2)⋅(x+2y)(−2)⋅(x+2y).
Step 2.1.1.1
Apply the distributive property.
2x+y=-22x+y=−2
-2x-2(2y)=(-2)(2)−2x−2(2y)=(−2)(2)
Step 2.1.1.2
Multiply 22 by -2−2.
2x+y=-22x+y=−2
-2x-4y=(-2)(2)−2x−4y=(−2)(2)
2x+y=-22x+y=−2
-2x-4y=(-2)(2)−2x−4y=(−2)(2)
2x+y=-22x+y=−2
-2x-4y=(-2)(2)−2x−4y=(−2)(2)
Step 2.2
Simplify the right side.
Step 2.2.1
Multiply -2−2 by 22.
2x+y=-22x+y=−2
-2x-4y=-4−2x−4y=−4
2x+y=-22x+y=−2
-2x-4y=-4−2x−4y=−4
2x+y=-22x+y=−2
-2x-4y=-4−2x−4y=−4
Step 3
Add the two equations together to eliminate xx from the system.
22 | xx | ++ | yy | == | -− | 22 | |||||
++ | -− | 22 | xx | -− | 44 | yy | == | -− | 44 | ||
-− | 33 | yy | == | -− | 66 |
Step 4
Step 4.1
Divide each term in -3y=-6−3y=−6 by -3−3.
-3y-3=-6-3−3y−3=−6−3
Step 4.2
Simplify the left side.
Step 4.2.1
Cancel the common factor of -3−3.
Step 4.2.1.1
Cancel the common factor.
-3y-3=-6-3
Step 4.2.1.2
Divide y by 1.
y=-6-3
y=-6-3
y=-6-3
Step 4.3
Simplify the right side.
Step 4.3.1
Divide -6 by -3.
y=2
y=2
y=2
Step 5
Step 5.1
Substitute the value found for y into one of the original equations to solve for x.
2x+2=-2
Step 5.2
Move all terms not containing x to the right side of the equation.
Step 5.2.1
Subtract 2 from both sides of the equation.
2x=-2-2
Step 5.2.2
Subtract 2 from -2.
2x=-4
2x=-4
Step 5.3
Divide each term in 2x=-4 by 2 and simplify.
Step 5.3.1
Divide each term in 2x=-4 by 2.
2x2=-42
Step 5.3.2
Simplify the left side.
Step 5.3.2.1
Cancel the common factor of 2.
Step 5.3.2.1.1
Cancel the common factor.
2x2=-42
Step 5.3.2.1.2
Divide x by 1.
x=-42
x=-42
x=-42
Step 5.3.3
Simplify the right side.
Step 5.3.3.1
Divide -4 by 2.
x=-2
x=-2
x=-2
x=-2
Step 6
The solution to the independent system of equations can be represented as a point.
(-2,2)
Step 7
The result can be shown in multiple forms.
Point Form:
(-2,2)
Equation Form:
x=-2,y=2
Step 8