Answer:
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
