Twice a number added to five gives 21.what is the number.?

Let's represent the number as x.

Twice the number is 2x.

The equation can be written as:

2x + 5 = 21

Subtracting 5 from both sides:

2x = 16

Dividing by 2:

x = 8

Therefore, the number is 8.

Let the number be x.
Twice the number is 2x.
Twice the number added to five is 2x + 5.
Given that 2x + 5 = 21.
Solving for x, we get:
2x = 21 - 5
2x = 16
x = 16/2
x = 8
Therefore, the number is 8.