Which of the following numbers is a prime number. 1,11,21,51

11 because it cannot be divided by any whole number besides 1.

11

Step-by-step explanation:

11 is a prime number

answer

d. 10

explanation

the distance from point y to wx is the height of the triangle.

using pythagoras theorem,

group similar terms to get,

this implies that,

take positive square root of both sides to get,

this implies that,