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maths fun
Colour the scalene triangle with yellow, isosceles with green, and equilateral with red in the
given figure.
(x + 1) (x + 2)

(x + 3)
(x – y)

(3 + x) (x – y) (x – y) (y + 3)

x
x x
y
y
y
y y x
x

A Pinch of History
It is said that algebra as a branch of Mathematics began about 1550 BC, i.e. more than 3500
years ago, when people in Egypt started using symbols to denote unknown numbers.

Around 300 BC, use of letters denote unknowns and forming expressions from them was quite
common in India. Many great Indian mathematicians, Aryabhatt (born 476AD), Brahmagupta
(born 598AD), Mahavira (who lived around 850AD) and Bhaskara II (born 1114AD) and others,
contributed a lot to the study of algebra. They gave names such as Beeja, Varna etc. to unknowns
and used first letters of colour names [E.g., ka from kala (black), nee from neela (blue)] to denote
them.

The Indian name for algebra, Beejaganit, dates back to these ancient Indian mathematicians.
The word ‘algebra’ is derived from the title of the book, ‘Aljebar w’al almugabalah’, written about
825 AD by an Arab mathematician, Mohammed Ibn Al Khowarizmi of Baghdad.

Mental Maths

1. What should be the value of k, if the value of 2x + x – k equals to 5, when x = 0?
2
2. There are a b orange saplings in a row of a field. If there are ab rows in the field. How many orange saplings
2
2
are there in the field? If a = 2 and b = 5, then find the number of saplings.
3. Will the value of 13p for p = –5 be greater than 13 or less than 13? Explain

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