Answer:
B. 4
Explanation:
4x + 5 = 21
1. move the 5 over to the 21 side. since its moving to the opposition side you change the 5 into -5.
4x = 21 - 5
2. then you do 21 - 5 which equals to 16
4x = 16
3. then you do 4 divided by what equals to 16 which is 4 so,
x = 4