Decimal Coefficients
Part of the Fundamentals section of Coddy's Algebra journey. Lesson 41 of 64.
A decimal coefficient can be written as a fraction. The equation 0.5x = 3 says that half of a number is 3. Since 0.5 = 1/2, dividing both sides by 0.5 is the same as multiplying both sides by 2.
x = 6
Multiplying by 2 undoes the coefficient 0.5. Check the answer: 0.5 × 6 = 3.
You can write the coefficient as a decimal or as a fraction, whichever is easier. Dividing by 0.5 and multiplying by 2 give the same answer, because 0.5 = 1/2. Other useful pairs are 0.25 = 1/4 and 0.2 = 1/5.
Challenge
MediumSolve the equation 0.25x = 4 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 First8Decimals and Percent
Decimal CoefficientsTwo-Step with DecimalsAdding a PercentPercent EquationsRecap: Decimals