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*Textbook p9 #25*The Prime factorisation of a number is 2^4 X 3^5 X 7^2 X 11.

Write down 3 factors of the number that are greater than 100.

(Hint: 16 X 11 = 176, which is a factor.)

Since 16=2x2x2x2, I will take 3^5 and 7^2 times 11.

3x3x3x3x3x11=2673

7x7x11=539

I still need another factor hence I will take 3^4 multiply by 11.

3x3x3x3x11=891

hence, the three factors are 2673, 539 and 891.

*:*

**Textbook p9 #26**The Prime factorisation of two numbers are 2 X 3^2 X 7^3 X 13 and3 X 7^2 X 13^3 X 17 .

Write down 3 common factors of the numbers.

The three common factors are 3,7 and 13.

Zhiqi

ReplyDeleteTextbook p9 #25:

Your answers are right.

Did you discover there's a systematic way of getting all the factors out? :P

Textbook p9 #26:

Could you share (the thinking behind) how you arrive at these 3 numbers?

Cheers!