KnowledgeBoat Logo
|

Mathematics

Solve :

2xyx+y=32\dfrac{2xy}{x + y} = \dfrac{3}{2}

xy2xy=310\dfrac{xy}{2x - y} = -\dfrac{3}{10}

x + y ≠ 0 and 2x - y ≠ 0

Linear Equations

18 Likes

Answer

Simplifying first equation :

2xyx+y=32x+yxy=2×23xxy+yxy=431y+1x=43 ……..(1)\Rightarrow \dfrac{2xy}{x + y} = \dfrac{3}{2} \\[1em] \Rightarrow \dfrac{x + y}{xy} = \dfrac{2 \times 2}{3} \\[1em] \Rightarrow \dfrac{x}{xy} + \dfrac{y}{xy} = \dfrac{4}{3} \\[1em] \Rightarrow \dfrac{1}{y} + \dfrac{1}{x} = \dfrac{4}{3} \text{ ……..(1)}

Simplifying second equation :

xy2xy=3102xyxy=1032xxyyxy=1032y1x=103 ……….(2)\Rightarrow \dfrac{xy}{2x - y} = -\dfrac{3}{10} \\[1em] \Rightarrow \dfrac{2x - y}{xy} = -\dfrac{10}{3} \\[1em] \Rightarrow \dfrac{2x}{xy} - \dfrac{y}{xy} = -\dfrac{10}{3} \\[1em] \Rightarrow \dfrac{2}{y} - \dfrac{1}{x} = -\dfrac{10}{3} \text{ ……….(2)}

Adding equations (1) and (2), we get :

1y+1x+(2y1x)=43+(103)1y+2y+1x1x=41033y=63y=3×36y=96=32.\Rightarrow \dfrac{1}{y} + \dfrac{1}{x} + \Big(\dfrac{2}{y} - \dfrac{1}{x}\Big) = \dfrac{4}{3} + \Big(-\dfrac{10}{3}\Big) \\[1em] \Rightarrow \dfrac{1}{y} + \dfrac{2}{y} + \dfrac{1}{x} - \dfrac{1}{x} = \dfrac{4 - 10}{3} \\[1em] \Rightarrow \dfrac{3}{y} = \dfrac{-6}{3} \\[1em] \Rightarrow y = \dfrac{3 \times 3}{-6} \\[1em] \Rightarrow y = -\dfrac{9}{6} = -\dfrac{3}{2}.

Substituting value of y in equation (1), we get :

132+1x=4323+1x=431x=43+231x=631x=2x=12.\Rightarrow \dfrac{1}{-\dfrac{3}{2}} + \dfrac{1}{x} = \dfrac{4}{3} \\[1em] \Rightarrow -\dfrac{2}{3} + \dfrac{1}{x} = \dfrac{4}{3} \\[1em] \Rightarrow \dfrac{1}{x} = \dfrac{4}{3} + \dfrac{2}{3} \\[1em] \Rightarrow \dfrac{1}{x} = \dfrac{6}{3} \\[1em] \Rightarrow \dfrac{1}{x} = 2 \\[1em] \Rightarrow x = \dfrac{1}{2}.

Hence, x=12 and y=32x = \dfrac{1}{2} \text{ and } y = -\dfrac{3}{2}.

Answered By

13 Likes


Related Questions