Here are some numbers:
4
6 7
15
21
Which number is a prime number?

7

Step-by-step explanation:

Prime numbers have a factor of 1 and itself.

4 is not prime because it has a factor of 2.

6 is not prime because it has factors 2 and 3.

7 is prime, it has 1 and 7 as its factors.

15 is not prime, it has factors of 3 and 5.

21 is not prime, it has factors of 3 and 7.

The only prime number from the list is 7, because the only factors it has is 1 and itself.

c. 27 units.

step-by-step explanation:

we are told that in circle a, ∠bae ≅ ∠dae.

we can see from our given diagram that in and ;

, as these are radii of our given circle.

therefore, by sas congruence postulate.

hence, side be will be equal to side de as corresponding parts of congruent triangles are congruent. so we can set an equation to find the value of x as:

now let us substitute x=17 in the expression for the length of be.

therefore, length of be will be 27 units and option c is the correct choice.