Ex 4.3

Chapter 4 Class 10 Quadratic Equations
Serial order wise

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### Transcript

Ex 4.3 ,3 Find the roots of the following equations: (ii) 1/(π₯ + 4)β1/(π₯ β 7)=11/30,π₯β β4, 7 1/(π₯ + 4)β1/(π₯ β 7)=11/30 ((π₯ β 7) β (π₯ + 4))/((π₯ + 4)(π₯ β 7)) = 11/30 (π₯ β 7 β π₯ β 4)/((π₯ + 4)(π₯ β 7)) = 11/30 (β11)/((π₯ + 4)(π₯ β 7))=11/30 β(11 Γ 30)/11=(π₯+4)(π₯β7) β30 = (x + 4) (x β 7) (x + 4) (x β 7) = β30 x (x β 7) + 4 (x β 7) = β30 x2 β 7x + 4x β 28 = β30 x2 β 3x β 28 = β30 x2 β 3x β 28 + 30 = 0 x2 β 3x + 2 = 0 Factorizing by quadratic method Comparing with ax2 + bx + c = 0 Here a = 1, b = β 3, c = 2 We know that D = b2 β 4ac D = ( β 3)2 β 4Γ1Γ2 D = 9 β 8 D = 1 Hence roots to equation are x = (β π Β± βπ·)/2π Putting the values x = (β (β 3) Β± β1)/(2 Γ 1) x =(3 Β± 1)/2 Solving Hence x = 2 and x = 1 are the roots of the equation