8.EE.C.7.b — Variables on Both Sides

What 8.EE.C.7.b Covers

Grade 8, Expressions & Equations, Cluster C (analyze and solve linear equations and pairs of simultaneous linear equations). Students solve linear equations with variables on both sides of the equal sign, including equations that require expanding expressions using the distributive property and combining like terms before the variable can be isolated.

Where It Fits

Builds directly on Grade 7's 7.EE.B.4.a (two-step equations, px + q = r) by adding a variable term to both sides of the equation. Leads into high school algebra's work solving equations and inequalities in one variable, including those with no solution or infinitely many solutions.

Common Mistakes

• Moving a variable term to the other side without changing its sign.
• Combining terms that aren't actually like terms (mixing constant and variable terms).
• Choosing to subtract the larger variable coefficient instead of the smaller one, which forces extra negative-number work later.