Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
secondary 3 | E Maths
One Answer Below
Anyone can contribute an answer, even non-tutors.
Would like to get help for part (b) pls.
I tried using (x -1)(x+1)=x2 - 1 but first this is unrelated to my ans in part (a) and secondly how to present it? Tks
Date Posted: 1 year ago
Views: 163
Every result ends with a “24”. And every multiplication has a “4” and a “6”
Take 2024 for example.
44 x 46 = 2024.
The second digit “4” in 44, the second digit “6” in 46 and the two digits “24” in 2024 always appear.
The remaining digits are not repetitive. Here, the remaining numbers are 4, 4 and 20.
Give you a clue. 4 times (4 + 1) = 20.
Take 2024 for example.
44 x 46 = 2024.
The second digit “4” in 44, the second digit “6” in 46 and the two digits “24” in 2024 always appear.
The remaining digits are not repetitive. Here, the remaining numbers are 4, 4 and 20.
Give you a clue. 4 times (4 + 1) = 20.
14 x 16 = 224
I take the “1” from 14, “1” from 16 and the first digit “2” from 224.
1 times (1 + 1) = 2.
24 x 26 = 624
I take the “2” from 24, “2” from 26 and “6” from 624.
2 times (2 + 1) = 6.
34 x 36 = 1224
I take the “3” from 34, “3” from 36 and “12” from 1224.
3 times (3 + 1) = 12.
Eventually, you will get these.
4 times (4 + 1) = 20
5 times (5 + 1) = 30
And so on.
I take the “1” from 14, “1” from 16 and the first digit “2” from 224.
1 times (1 + 1) = 2.
24 x 26 = 624
I take the “2” from 24, “2” from 26 and “6” from 624.
2 times (2 + 1) = 6.
34 x 36 = 1224
I take the “3” from 34, “3” from 36 and “12” from 1224.
3 times (3 + 1) = 12.
Eventually, you will get these.
4 times (4 + 1) = 20
5 times (5 + 1) = 30
And so on.
See 1 Answer
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
You will get 100n (n + 1) + 24.
The “100” is just there to get multiplied by n (n + 1) so the result for n (n + 1) will go into the hundreds or even thousands.
For example, in 1224,
1224
= 1200 + 24
= 100 (12) + 24
= 100 (3) (3 + 1) + 24
The “100” is just there to get multiplied by n (n + 1) so the result for n (n + 1) will go into the hundreds or even thousands.
For example, in 1224,
1224
= 1200 + 24
= 100 (12) + 24
= 100 (3) (3 + 1) + 24
Date Posted:
1 year ago
Thank u v much
360 Tutoring Program