Interactive
Curated OER

Example and Steps to Solving Linear Systems Using Substitution

8th - 11th
For this linear equation worksheet, students solve five systems of linear equations using the substitution method.  Three examples with steps to solve are provided.
Interactive
National Council of Teachers of Mathematics

Nctm: Illuminations: Resources for Teaching Math: Algebra Tiles

9th - 10th Standards
Try this hands-on approach to solving algebra problems with this interactive website. Students are able to "solve equations, substitute in variable expressions, expand, and factor".