Algebra
SIMULTANEOUS EQUATIONS
Systems of two equations involving two unknowns can also be solved by comparison.
Step 1.
Solve each equation for the same unknown in terms of the other unknown.
Step 2.
Set the two expressions obtained equal to each other.
Step 3.
Solve the resulting equation for the one remaining unknown.
Step 4.
Find the value of the other unknown by substituting the value of the first
unknown into one of the original equations.
Step 5.
Check the solution by substituting the values of the two unknowns into the
other original equation.
Example:
Solve the following system of equations by comparison.
5x + 6y = 12
3x + 5y = 3
Solution:
Step 1.
Solve both equations for x.
5x
6y
12
5x
12
6y
5x
5
12
6y
5
x
12
6y
5
3x
5y
3
3x
3
5y
3x
3
3
5y
3
x
3
5y
3
Rev. 0
Page 37
MA-02
