This would be displayed as 11 - 5k
This cannot be solved, however, without knowing the value of k, or at least what the expression is equal to.
2.5 divided by 2 equals 1.25 so each side equals 1.25
Do you mean checking your work? In that case it would be 9*20.
25d^2-30d-35d+42=25d^2-65d+42.