10th Maths 4.2
NCERT Class 10th solution of Exercise 4.1 NCERT Class 10th solution of Exercise 4.3 NCERT Class 10th solution of Exercise 4.4 NCERT Class 10th Maths Projects Exercise 4.2 Q1. Find the roots of the following quadratic equation by factorisation : i) `x^2-3x-10=0,` ii) `2x^2+x-6=0,` iii) `sqrt2x^2+7x+5sqrt2=0,` iv) `2x^2-x+1/8=0,` v) `100x^2-20x+1=0.` Sol. : i) `x^2-3x-10=0` `x^2-5x+2x-10=0` `x(x-5)+2(x-5)=0` `(x-5)(x+2)=0` `x-5=0` `x=5` `x+2=0` `x=-2` Answer : `x=5, x=-2`. ii) `2x^2+x-6=0` `2x^2+4x-3x-6=0` `2x(x+2)-3(x+2)=0` `(x+2)(2x-3)=0` `x+2=0` `x=-2`, `2x-3=0` `x=3/2` Answer : `x=-2, x=3/2`. iii) `sqrt2x^2+7x+5sqrt2=0` `sqrt2x^2+5x+2x+5sqrt2=0` `x(sqrt2x+5)+sqrt2(sqrt2x+5)=0` `(sqrt2x+5)(x+sqrt2)=0` `sqrt2x+5=0` `x=-5/sqrt2` `x+sqrt2=0` `x=-sqrt2` Answer : `x=-5/sqrt2, x=-sqrt2`. iv) `2x^2-x+1/8=0` `16x^2-8x+1=0` `16x^2-4x-4x+1=0` `4x(4x-1)-1(4x-1)=0` `(4x-1)(4x-1)=0` `(4x-1)^2=0` `4x-1=0` `x=1/4` Answer : each `x=1/4`. v) `100x^2-20x+1=0` `100x^2-10x-10x+1=0` `10x(10x-1)-1(10x-1)=0...