ax + by = c has two letters and no formula to recognise, which makes it the plainest form of the question: get one letter on its own. These free printable worksheets give eight equations like 5x + 8y = 6 and name the letter to solve for — x on some questions, y on others.
If they get stuck
The answer key prints on a separate page.
The method is two moves, the same two every time. Move the other term across by subtracting it from both sides, then divide by the coefficient of the letter you want. Solving 5x + 8y = 6 for y gives 8y = 6 − 5x, then y = (6 − 5x)/8, and the key writes both lines with the fraction stacked. The common slip is dividing only part of the right-hand side — writing 6 − 5x/8 — and a stacked fraction, with all of 6 − 5x above the bar, is how the page shows that every term was divided.
Which letter is asked for changes from question to question, and every sheet asks for both. Solving 5x + 8y = 18 for x is the same two moves with the roles swapped, 5x = 18 − 8y, and a student who has only ever isolated y tends to move the wrong term. The coefficients run from 2 to 9 and are never equal, so the two letters never mirror each other.
Solve 5x + 8y = 6 for y