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Ex 4.2, 1 - Find roots by factorization (i) x2 - 3x - 10 = 0 - Ex 4.2

  1. Chapter 4 Class 10 Quadratic Equations
  2. Serial order wise
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Ex 4.2 ,1 Find the roots of the following quadratic equations by factorization: (i) x2 – 3x – 10 = 0 x2 – 3x – 10 = 0 We factorize using splitting the middle term method x2 + 2x – 5x – 10 = 0 x (x + 2) – 5(x + 2) = 0 (x – 5) (x + 2) = 0 Hence , x = 5 and x = – 2 are the roots of equation Ex 4.2 ,1 Find the roots of the following quadratic equations by factorization: (ii) 2x2 + x – 6 = 0 2x2 + x – 6 = 0 We factorize using splitting the middle term method 2x2 + 4x – 3x – 6 = 0 2x (x + 2) – 3(x + 2) = 0 (2x – 3) (x + 2) = 0 So, x = 3/2 & x = – 2 are the roots of equation Ex 4.2 ,1 Find the roots of the following quadratic equations by factorization: (iii) √2 x2 + 7x + 5 √2 = 0 √2 x2 + 7x + 5 √2 = 0 We will factorize by splitting the middle term method √2 𝑥2+2𝑥+5𝑥+5√2=0 √2 𝑥2+(√2 ×√2)𝑥+5𝑥+5√2=0 √2 𝑥(𝑥+√2)+5(𝑥+√2)=0 (√2 𝑥+5)(𝑥+√2)=0 So, x = (−5)/√2 𝑎𝑛𝑑 𝑥=−√2 are the roots of equation Ex 4.2 ,1 Find the roots of the following quadratic equations by factorization: (iv) 2x2 – x + 1/8=0 2x2 – x + 1/8=0 Multiplying both sides by 8 8 × 2x2 – 8x + 8 × 1/8="8 ×" 0 16x2 – 8x + 1 = 0 We factorize using splitting the middle term method 16x2 – 4x – 4x + 1 = 0 4x (4x – 1) – 1 (4x – 1) = 0 (4x – 1) (4x – 1) = 0 So, x = 1/4 & x = 1/4 are the roots of equation Ex 4.2 ,1 Find the roots of the following quadratic equations by factorization: (v) 100 x2 – 20x + 1 = 0 100 x2 – 20x + 1 = 0 We factorize using splitting the middle term method 100 x2 – 10x – 10x + 1 = 0 10x (10x – 1) – 1 (10x – 1) = 0 (10x – 1) (10x – 1) = 0 So, x = 1/10 & x = 1/10 are the roots of equation

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He provides courses for Mathematics from Class 9 to 12. You can ask questions here.
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