Question

class 9 th mai sub maths ke lesson no 1 ke saare formule bta do​

Answer 1

Answer:

There are no such formulas but there are identities to simplify rational and irrational numbers . These identities are nothing new but same as what we have studied in class eighth

Step-by-step explanation:

I'm listing them. bellow :

$\sqrt{ab} = \sqrt{a} \sqrt{b}$

$\sqrt{ \frac{a}{b} } = \frac{ \sqrt{a} }{ \sqrt{b} }$

$( \sqrt{a} + \sqrt{b} )( \sqrt{a} - \sqrt{b} ) = a - b$

$(a + \sqrt{b} )(a - \sqrt{b} ) = {a}^{2} - b$

$( \sqrt{a} + \sqrt{b} )( \sqrt{c} + \sqrt{d} ) = \sqrt{ac} + \sqrt{ad} + \sqrt{bc} + \sqrt{bd}$

${( \sqrt{a} + \sqrt{b}) }^{2} = a + \sqrt{2ab} + b$

These were some identities of class 9 chapter1 . These are just derived from algebraic identities which we have already studied in earlier classes . according to my ncert book there is no more such extra formula in chapter called Number System . As the whole chapter is based on concepts and tricks so you just need to understand each questions by heart . Its one of the most easiest chapter of class9 and its well bellow anyone's level . So you will do good in that . All the best .