3 (n - 5) - (6 -2n) = 4n

 n = 21

Step-by-step explanation:

Use distributive rule: a(b + c) = a*b + a*c

3(n -5) - (6 - 2n) = 4n

3*n - 3*5 + 6*(-1) - 2n *(-1) = 4n

3n  - 15 - 6 + 2n = 4n             {add like term in LHS}

3n + 2n - 15 - 6 = 4n

            5n - 21  = 4n              {add 21 to both sides}

       5n -21 + 21 = 4n +21

                     5n = 4n + 21         {subtract 4n from both sides}

             5n - 4n = 4n -4n +21

   n = 21

the answer is b.

step-by-step explanation:

by the trigonometric ratio tangent, tangent equals opposite divided by adjacent.

therefore, tan(50) equals ac/3

multiply each side by 3 to get: ac=3tan(50)

the answer is b.

b

step-by-step explanation: