Crack The Safe - Solving Linear Equations

Two “Crack The Safe” activities on solving linear equations (one on two-step and one on more than two-step, including fractions and brackets). These contain six questions but six possible answers for each question meaning that students can self-check their answers (are they in the list of possible answers?) whilst the teacher can help those who require it. I use these as starters and plenaries but that is obviously up to you.