What you’ll learn
Write simple equations from situations.
Key idea
An equation states the relationship, not just a solved input; a candidate must match every operation.
A solved value is not the requested relationship; an equation fitting one input can still model the wrong operations.
Worked example
Enter the exact value or ordered values in the format requested below.
A number x is multiplied by 2, then 2 is added, producing 16. Write the relationship as an equation; do not give only a solution.
- Multiply x by 2, then separately add 2 to form 2x+2.
- Set this expression equal to the supplied result 16; x=7 checks the relationship.
Answer: 2x+2=16
Quick Check
Choose which candidate representation satisfies the requirements of 'Write simple equations from situations' and justify the choice.
Select an equation meeting both constraints: multiply x by 2, add 5 separately, and obtain 15 at x=5.