Note that the variable x has already been isolated in the first equation. Therefore, it is easier to substitute the expression equivalent to x in the first equation into the second equation in order to solve the system.
x= 8y-4 & (I) x+8y=6 & (II) [1.5em]
substitution ↓ [0.2em]
x= 8y-4 & (I) 8y-4+8y=6 & (II)
Extra
Steps of the Substitution Method
Let's review the steps that we need to follow when solving a system of equations by the Substitution Method.
What is done?
Step I
Isolate one variable in any of the equations.
Step II
Substitute the equivalent expression of the isolated variable into the other equation. This will result in one equation in one variable.
Step III
Solve the obtained equation in one variable.
Step IV
Substitute the result into one of the original equations to find the other variable.
