Solve the following equation by factorisation:
2x2−5x+2=0,x\dfrac{2}{x^2} - \dfrac{5}{x} + 2 = 0, xx22−x5+2=0,x ≠ 0
17 Likes
Given,
2x2−5x+2=0⇒2−5x+2x2x2=0⇒2−5x+2x2=0×x2⇒2x2−5x+2=0⇒2x2−4x−x+2=0⇒2x(x−2)−1(x−2)=0⇒(2x−1)(x−2)=0 (Factorising left side) ⇒2x−1=0 or x−2=0 (Zero-product rule) ⇒2x=1 or x=2x=12 or x=2\dfrac{2}{x^2} - \dfrac{5}{x} + 2 = 0 \\[1em] \Rightarrow \dfrac{2 - 5x + 2x^2}{x^2} = 0 \\[1em] \Rightarrow 2 - 5x + 2x^2 = 0 \times x^2 \\[1em] \Rightarrow 2x^2 - 5x + 2 = 0 \\[1em] \Rightarrow 2x^2 - 4x - x + 2 = 0 \\[1em] \Rightarrow2x(x - 2) - 1(x - 2) = 0 \\[1em] \Rightarrow (2x - 1)(x - 2) = 0 \text{ (Factorising left side) } \\[1em] \Rightarrow 2x - 1 = 0 \text{ or } x - 2 = 0 \text{ (Zero-product rule) } \\[1em] \Rightarrow 2x = 1 \text{ or } x = 2 \\[1em] x = \dfrac{1}{2} \text{ or } x = 2 \\[1em]x22−x5+2=0⇒x22−5x+2x2=0⇒2−5x+2x2=0×x2⇒2x2−5x+2=0⇒2x2−4x−x+2=0⇒2x(x−2)−1(x−2)=0⇒(2x−1)(x−2)=0 (Factorising left side) ⇒2x−1=0 or x−2=0 (Zero-product rule) ⇒2x=1 or x=2x=21 or x=2
Hence, the roots of given equation are 12\dfrac{1}{2}21 , 2.
Answered By
8 Likes
x2−(1+2)x+2=0x^2 - (1 + \sqrt{2})x + \sqrt{2} = 0x2−(1+2)x+2=0
x+1x=2120x + \dfrac{1}{x} = 2\dfrac{1}{20}x+x1=2201
x215−x3−10=0.\dfrac{x^2}{15} - \dfrac{x}{3} -10 = 0.15x2−3x−10=0.
3x−8x=23x - \dfrac{8}{x} = 23x−x8=2