SIMULTANEOUS EQUATIONS
Algebra
Step 4.
Substitute x = 6 into one of the original equations and solve for y.
5x
6y
12
5(6)
6y
12
30
6y
12
6y
12
30
6y
18
6y
6
18
6
y
3
Step 5.
Check the solution by substituting x = 6 and y = -3 into the other original
equation.
3x
5y
3
3(6)
5(
3)
3
18
15
3
3
3
Thus, the solution checks.
Systems of two equations involving two unknowns can also be solved by substitution.
Step 1.
Solve one equation for one unknown in terms of the other.
Step 2.
Substitute this value into the other equation.
Step 3.
Solve the resulting equation for the value of 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.
MA-02
Page 34
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