Q1 of 95 Page 68

Write number like this:


Explain why this is so, using algebra.

Let the first number in the square be x, the others can be filled in as below,


Diagonal products: x (x+6) = x2 + 6x


(x+5)(x+1) = x(x+1) + 5(x+1) = (x2 + x) + (5x +5) = x2 + 6x + 5


Clearly, the difference between the two diagonal products is always 5.


More from this chapter

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1

Write number like this:


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 1

Write number like this:


Explain why this is so, using algebra.

 1

Write number like this:


Instead of a square of four numbers, take a square of nine numbers and mark only the numbers at the four corners.



What is the difference of diagonal products? Explain using algebra.

 1

Write number like this:


Instead of a square of four numbers, take a square of nine numbers and mark only the numbers at the four corners.



What is the difference of diagonal products? Explain using algebra.