Question

How do you decide which variable to isolate in order to use the substitution method to solve a system of linear equation?​

Answer 1

It doesn’t really matter which variable you isolate first but usually you would use the one that’s by itself already. like for example one of the equations was y = 8. you would already have your y solve for so you would just have to plug that in for y in the other equation. personally, i usually do x first unless one of the equations has either x or y by itself already. i think its easier to just do x first and then solve for y after that, but it just depends on what the equations are; sometimes it might be easier to just do y first. hope this helps!

Answer 2

Sample Response: Look to see if any of the variables do not have a coefficient. That would be the most efficient variable to isolate. If there is more than one variable with no coefficient, it doesn’t matter which one you isolate. Isolate the variable and use substitution to solve the system of equations.

Explanation: