How it works
Twelve equations like 9x + 9 = 7x + 25 open this free page, three work lines under each. Sheet type adds negatives, one bracket, brackets on both sides, fraction answers, and equations with no solution or every solution.
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Collect the letter on one side
Take the smaller x term from both sides so the letter stays positive: 9x + 9 = 7x + 25 becomes 2x + 9 = 25, then 2x = 16 and x = 8. The key prints the collected line, 2x = 16, then 16 ÷ 2 = 8, then both sides checked: 81 and 81.
When the letters cancel
If the x terms match, they vanish. 3x − 2 = 3x + 12 leaves −2 = 12, which is false, so there is no solution. 2(x + 1) = 2x + 2 leaves 2 = 2, true for every number. Common Core 8.EE.C.7a asks for all three outcomes.
- Print Fraction answers after Negative numbers: 6x − 11 = 3x − 1 gives x = 10/3, and pupils who expect whole numbers stop checking.
- On No solution and all real numbers, ask pupils to write the last line, such as −2 ≠ 12, before the words.
Questions and answers
Which side should the x go on?
Either works, but moving the smaller x term keeps the coefficient positive. In 4y + 17 = 8y − 15, take 4y away: 17 = 4y − 15, so 32 = 4y and y = 8. The key's −4y = −32 gives the same answer.
Are the answers always whole numbers?
On eight of the ten sheet types, yes. Fraction answers and Fraction answers with a bracket give answers such as 10/3 and 5/2, always in lowest terms.
How do I print it as a PDF?
Press Print and choose Save as PDF as the printer. The answer key follows the sheet on its own page; untick Answer key to leave it out.