3.2 Solving Linear Systems Algebraically. 2 Methods for Solving Algebraically. Substitution Method (used mostly when one of the equations has a variable with a coefficient of 1 or -1) Elimination Method. Substitution Method.
(used mostly when one of the equations has a variable with a coefficient of 1 or -1)
Solve the 1st eqn for y.
Now substitute 3x-13 in for the y in the 2nd equation.
Now, solve for x.
Now substitute the 2 in for x in for the equation from step 1.
Plug in to check soln.Ex: Solve using substitution method
Multiply the entire 2nd eqn. by 3 so that the y’s will cancel.
Now add the 2 equations.
and solve for the variable.
Substitute the -7 in for x in one of the original equations.
Now write as an ordered pair.
Plug into both equations to check.Ex: Solve using elimination method.