First, subtract color(red)(7/12) from each side of the equation to solve for m:
m + 7/12 - color(red)(7/12) = - 5/18 - color(red)(7/12)
m + 0 = - 5/18 - color(red)(7/12)
m = - 5/18 - color(red)(7/12)
To add/subtract the two factions we need to get them over a common denominator:
m = - (2/2 xx 5/18) - (3/3 xx color(red)(7/12))
m = -10/36 - 21/36
m = -31/36
To check the solution, substitute -31/36 for m in the original equation and calculate the result for both sides of the equation to ensure they are equal:
m + 7/12 = -5/18 becomes:
-31/36 + 7/12 = -5/18
-31/36 + (3/3 xx 7/12) = -5/18
-31/36 + 21/36 = -5/18
-10/36 = -5/18
-(2 xx 5)/(2 xx 18) = -5/18
-(color(red)(cancel(color(black)(2))) xx 5)/(color(red)(cancel(color(black)(2))) xx 18) = -5/18
-5/18 = -5/18
Because both sides of the equation are equal the result checks out.