Question

maths 8th class first semester text book 30 formulas​

Answer 1

Answer:

Important Formulas in Algebra

a2 – b2 = (a – b)(a + b)

(a+b)2 = a2 + 2ab + b2

a2 + b2 = (a – b)2 + 2ab.

(a – b)2 = a2 – 2ab + b2

(a + b + c)2 = a2 + b2 + c2 + 2ab + 2ac + 2bc.

(a – b – c)2 = a2 + b2 + c2 – 2ab – 2ac + 2bc.

(a + b)3 = a3 + 3a2b + 3ab2 + b3 ; (a + b)3 = a3 + b3 + 3ab(a + b)

(a – b)3 = a3 – 3a2b + 3ab2 – b3

Rational number

In mathematics, a rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number.

Exponent

Exponents Formula. In the expression, a^{2}, a is known as base and 2 is known as the exponent. An exponent represents the number of times the base to be multiplied. For example, in a^{2}, a will be multiplied twice, i.e., a \times a and silimarlt a^{3} = a \times a