Examples
x+y=2x+y=2 , x-2y=4x−2y=4
Step 1
Step 1.1
Multiply each equation by the value that makes the coefficients of xx opposite.
x+y=2x+y=2
(-1)⋅(x-2y)=(-1)(4)(−1)⋅(x−2y)=(−1)(4)
Step 1.2
Simplify.
Step 1.2.1
Simplify the left side.
Step 1.2.1.1
Simplify (-1)⋅(x-2y)(−1)⋅(x−2y).
Step 1.2.1.1.1
Apply the distributive property.
x+y=2x+y=2
-1x-1(-2y)=(-1)(4)−1x−1(−2y)=(−1)(4)
Step 1.2.1.1.2
Simplify the expression.
Step 1.2.1.1.2.1
Rewrite -1x−1x as -x−x.
x+y=2x+y=2
-x-1(-2y)=(-1)(4)−x−1(−2y)=(−1)(4)
Step 1.2.1.1.2.2
Multiply -2−2 by -1−1.
x+y=2x+y=2
-x+2y=(-1)(4)−x+2y=(−1)(4)
x+y=2x+y=2
-x+2y=(-1)(4)−x+2y=(−1)(4)
x+y=2x+y=2
-x+2y=(-1)(4)−x+2y=(−1)(4)
x+y=2x+y=2
-x+2y=(-1)(4)−x+2y=(−1)(4)
Step 1.2.2
Simplify the right side.
Step 1.2.2.1
Multiply -1−1 by 44.
x+y=2x+y=2
-x+2y=-4−x+2y=−4
x+y=2x+y=2
-x+2y=-4−x+2y=−4
x+y=2x+y=2
-x+2y=-4−x+2y=−4
Step 1.3
Add the two equations together to eliminate xx from the system.
xx | ++ | yy | == | 22 | ||||||
++ | -− | xx | ++ | 22 | yy | == | -− | 44 | ||
33 | yy | == | -− | 22 |
Step 1.4
Divide each term in 3y=-23y=−2 by 33 and simplify.
Step 1.4.1
Divide each term in 3y=-23y=−2 by 33.
3y3=-233y3=−23
Step 1.4.2
Simplify the left side.
Step 1.4.2.1
Cancel the common factor of 33.
Step 1.4.2.1.1
Cancel the common factor.
3y3=-23
Step 1.4.2.1.2
Divide y by 1.
y=-23
y=-23
y=-23
Step 1.4.3
Simplify the right side.
Step 1.4.3.1
Move the negative in front of the fraction.
y=-23
y=-23
y=-23
Step 1.5
Substitute the value found for y into one of the original equations, then solve for x.
Step 1.5.1
Substitute the value found for y into one of the original equations to solve for x.
x-23=2
Step 1.5.2
Move all terms not containing x to the right side of the equation.
Step 1.5.2.1
Add 23 to both sides of the equation.
x=2+23
Step 1.5.2.2
To write 2 as a fraction with a common denominator, multiply by 33.
x=2⋅33+23
Step 1.5.2.3
Combine 2 and 33.
x=2⋅33+23
Step 1.5.2.4
Combine the numerators over the common denominator.
x=2⋅3+23
Step 1.5.2.5
Simplify the numerator.
Step 1.5.2.5.1
Multiply 2 by 3.
x=6+23
Step 1.5.2.5.2
Add 6 and 2.
x=83
x=83
x=83
x=83
Step 1.6
The solution to the independent system of equations can be represented as a point.
(83,-23)
(83,-23)
Step 2
Since the system has a point of intersection, the system is independent.
Independent
Step 3