Math, asked by niti75, 11 months ago

solve 9x-7/3x+5=3x-4/x+6​

Answers

Answered by tavilefty666
25

Step-by-step explanation:

\frac{9x-7}{3x+5}=\frac{3x-4}{x+6}\\ by\  cross-multiplication\ \\(9x-7)(x+6)=(3x+5)(3x-4)\\9x^2+54x-7x-42=9x^2-12x+15x-20\\9x^2+47x-42=9x^2+3x-20\\47x-3x=-20+42\\44x=22\\ \therefore\ x=\frac{1}{2}

Answered by LovelyG
30

Answer:

\large{\underline{\boxed{\sf x =  \frac{1}{2} \:  \: or \:  \:  0.5}}}

Step-by-step explanation:

 \sf  \dfrac{9x - 7}{3x + 5}  =  \dfrac{3x - 4}{x + 6}

On cross multiplying, we get :-

\rightarrow \sf  (9x - 7)(x + 6) = (3x + 5)(3x - 4) \\  \\ \rightarrow \sf 9x {}^{2}  + 54x - 7x - 42 = 9x {}^{2}  - 12x + 15x - 20 \\  \\ \rightarrow \sf 9x {}^{2}  + 47x - 42 = 9x {}^{2}  + 3x - 20 \\  \\ \rightarrow \sf 9x {}^{2}  + 47x - 9x {}^{2}  - 3x = 42 - 20 \\  \\  \rightarrow \sf 44x = 22 \\  \\ \rightarrow \sf x =  \frac{22}{44}  \\  \\ \boxed{ \bf \therefore x =  \frac{1}{2} \:  \: or \:  \:  0.5  }

Verification:

Substitute the value of x in the given equation:-

 \sf  \frac{9x - 7}{3x + 5}  =  \frac{3x - 4}{x + 6} \\  \\ \sf  \frac{9(0.5) - 7}{3(0.5) + 5}  =  \frac{3(0.5) - 4}{0.5  + 6}  \\  \\ \sf  \frac{4.5 - 7}{1.5 + 5}  =  \frac{1.5 - 4}{6.5}  \\  \\  \sf \frac{ - 2.5}{6.5}  =  \frac{ - 2.5}{6.5}  \\  \\ \bf  \therefore lhs = rhs

Hence, the answer is ½ or 0.5


tavilefty666: nicely explained
tavilefty666: even I didn't get this idea
LovelyG: :)
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