If sum of three consecutive integers is-21,find the largest

If sum of three consecutive integers is-21,find the largest integer.
If sum of three consecutive integers is-21,find the largest integer.第二The sum of two numbers,A and B,is 33.If 3/5(分数,3在5上面）of A is equal to one half of B,find the two nembers.
顺便给个答案,这个是立方程和解方程,