Question

How many prime numbers less than 100 and greater than 3 are of the form 4x+1 5y-1?

Answer 1

Answer:

list of primes which are of form 4x + 1 is

5 13 17 29 37 41 53 57 61 73 89 97 .

list of primes which are of form 5x - 1 is

19 29 59 79 89 .

Step-by-step explanation:

Since

If we put different values for x in

4x + 1

we get

4(1) + 1 = 5

4(2) + 1 = 9

4(3) + 1 = 13

4(4) + 1 = 17

4(5) + 1 = 21

4(6) + 1 = 25

4(7) + 1 = 29

4(8) + 1 = 33

4(9) + 1 = 37

4(10) + 1 = 41

4(11) + 1 = 45

4(12) + 1 = 49

4(13) + 1 = 53

4(14) + 1 = 57

4(15) + 1 = 61

4(16) + 1 = 65

4(17) + 1 = 69

4(18) + 1 = 73

4(19) + 1 = 77

4(20) + 1 = 81

4(21) + 1 = 85

4(22) + 1 = 89

4(23) + 1 = 93

4(24) + 1 = 97

4(25) + 1 = 101

So list of primes which are of form 4x + 1 is

5 13 17 29 37 41 53 57 61 73 89 97 .

Similarly

NOW putting different values for x in

5x - 1

We get

4 9 14 19 24 29 34 39 44 49 54 59 64 69 74 79 84 89 94 99

And list of primes is

19 29 59 79 89

So list of primes which are of form 5x - 1 is

19 29 59 79 89