Parentheses on One Side
Part of the Fundamentals section of Coddy's Algebra journey. Lesson 32 of 64.
To solve 3(x + 2) = 2x + 10, expand the bracket first, then collect the x-terms.
3x + 6 = 2x + 10
x + 6 = 10
x = 4
Check: 3(4 + 2) = 18 and 2 × 4 + 10 = 18.
Here you must distribute before you collect. While the x is inside the bracket, subtracting 2x from both sides gives 3(x + 2) - 2x, which is no simpler. So expand the brackets, collect the like terms on each side, then collect across the equals sign. This order solves every linear equation.
Challenge
MediumSolve the equation 2(x + 5) = x + 13 for x.
Try it yourself
Solve for x
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Fundamentals
1What an Equation Is
The EquationFinding the UnknownThe Same to Both SidesSolved Means AloneRecap: First Equations4Two-Step Equations
Two Layers to UndoSubtract, Then DivideAdd, Then DivideA Division InsideNegatives in Two StepsRecap: Two-Step Equations2One-Step Equations
Undoing AdditionUndoing SubtractionUndoing MultiplicationUndoing DivisionInverse OperationsRecap: One-Step Equations5Tidying First
Like TermsTerms and Numbers MixedThe Distributive PropertyDistributing a SubtractionTidy, Then SolveRecap: Tidying First6Variables on Both Sides
x on Both SidesGathering the x'sNumbers and x's EverywhereParentheses on One SideWhen x Is NegativeRecap: Both Sides