Slide24.JPG Slide25.JPG

You saved atleast 2 minutes of distracting ads by going ad-free. Thank you :)

You saved atleast 2 minutes by viewing the ad-free version of this page. Thank you for being a part of Teachoo Black.


Transcript

Ex 1.1, 6 Explain why 7 × 11 × 13 + 13 and 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 are composite numbers. Checking 7 × 11 × 13 + 13 7 × 11 × 13 + 13 = 13 × ( 7 × 11 + 1) = 13 × (77 + 1) = 13 × 78 = 13 × 13 × 3 × 2 Since it has more than two factors (13, 3, 2, 1, 13 × 78), ∴ It is a composite number Checking 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 Now, 7 × 6 × 5 × 4 × 3 × 2 × 1 + 5 = 5 × (7 × 6 × 4 × 3 × 2 × 1 + 1) = 5 × (1008 + 1) = 5 × 1009 Since it has more than two factors (5, 1009, 1 , 5 × 1009), ∴ It is a composite number

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo