How do you solve by substitution # x+-y=1# and #-2x+y=4#?
1 Answer
The problem has two solutions:
Explanation:
To solve by substitution, we isolate one of the variables in one equation, and use that to solve the other equation.
Case 1:
Our system is:
Since the first equation is easier to work with, we can isolate a variable there.
Now, we substitute
We now know the value of
Therefore, the solution to Case 1 is
Case 2:
Our system is:
Like before, we isolate one of the variables in one equation and solve using the other equation.
At this point, we know the
Therefore the solution to case 2 is
The problem has two solutions: