Question

Tìm x: \(\frac{4x-1}{9x-8}=\frac{2x+3}{4x+5}\)

Answer 1

(4x-1)(4x+5)=(9x-8)(2x+3)

16x²+16x-5=18x²+11x-24

-2x²+5x+19=0

2x²-5x-19=0

...

Answer 2

 

\(\frac{4x-1}{9x-8}=\frac{2x+3}{4x+5}\)

=> \(\left(4x-1\right)\left(4x+5\right)=\left(2x+3\right)\left(9x-8\right)\)

=> \(16x^2+20x-4x-5=18x^2-16x+27x-24\)

=> \(16x^2+16x-5=18x^2+11x-24\)

=>  \(-5+24=18x^2-16x^2+11x+16x\)

=> \(19=2x^2-27x\)