A Division Inside
Part of the Fundamentals section of Coddy's Algebra journey. Lesson 20 of 64.
In x/2 + 3 = 8, the unknown is divided by 2, and then 3 is added. Undo the operations in reverse order. Subtract 3 from both sides first. Then undo the division by multiplying both sides by 2:
x/2 = 5
x = 10
Check: 10/2 + 3 = 8, which is true.
There is another way. Multiply every term by 2 to get x + 6 = 16, then subtract 6. Both methods give the same answer in two steps. Clearing the denominators first is useful when an equation has several fractions.
Challenge
EasySolve the equation x/4 + 5 = 9 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 First