1: i am thinking of a number. When it is increased by 7, it equals 21. what is my number

N = 28
N = 14
N = 7
N = 147

2: i am thinking of a number. It is multiplied by 9. The product is 27. What is my number

N = 36
N = 18
N = 3
N = 4

3: Translate the following sentence into an equation. Then solve the equation
The difference of a number and 7 an 21

21 - 7 = n; n =14

n + 7 = 21 ; n=14

n + = 21 ; n = 28

21 - 7 = n; n =14