For number 1) You need to get m alone, so you must add 4.4 to 2.6. For number 2) Same thing as #1 For number 3) You must get c alone, you need to divide 10 by 2.5 For number 4) Same as #3 For number 5) You need to get t alone, so you must multiply both sides by 2.5 For number 6) Same as #5