1 - 1/2c = 6
1 -1 - 1/2c = 6 -1 (subtract 1 on both sides)
-1/2c = 5 (next do the inverse operation)
c = 5 ÷ 1/2
c = -10
to check your answer substitute the value of c in the equation;
1- 1/2c = 6
1- 1/2(-10) = 6
1 + 5 = 6
6 =6
