Question

How to:Solve systems of equations (substitution method)

Answer 1

I’ll be posting some links, definitions, and I’ll be working out some examples, so bear with me.

The first thing you need to know about solving systems of equations by the substitution method, is that you need to know what the substitution method is.

https://www.mathsisfun.com/definitions/substitution.html

That link up there would be the definition of substitution. What you do when you use the substitution method, is just putting numbers in for variables. Or substituting them. For example, if you have an equation that says this \[x +23=y\]. The problem also gives you this. \[Y=54\]. Since we have a y in this equation (x+23=y) we can put in, or substitute 54 for y. So now we have \[x +23=54\]. We’re getting closer to our answer now. But we still need to figure out what x is. To do that, we need to get x by himself. So again, we subtract 23 from each side.
23-23=0, and 54-23=31. So x=31. That would be how I solve that problem using substitution. For a little more harder problems, Take a look at these videos.

https://www.khanacademy.org/math/algebra/systems-of-eq-and-ineq/fast-systems-of-equations/v/solving-linear-systems-by-substitution

and

https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-systems-topic/cc-8th-systems-with-substitution/v/solving-systems-by-substitution-1

I’ve also used this worksheet to help me out with this method.