Question

tìm x:

 (4x-3+2x)(8x+1)=27

Answer 1

(4x-3+2x)(8x+1)=27

(6x-3)(8x+1)=27

48x+6x-24x-3=27

30x-3=27

30x=27+3=30

x=30/30=1

Answer 2

<=> (6x-3)(8x+1)=27

<=> 3(2x-1)(8x+1)=27

<=> 16x²+2x-8x-1=9

<=> 16x²-6x-10=0

<=> 8x²-3x-5=0

<=> 8x²-8-3x+3=0

<=> 8(x-1)(x+1)-3(x-1)=0

<=> (x-1)(8x+8-3)=0

<=> (x-1)(8x+5)=0

=> \(\hept{\begin{cases}x_1=1\\x_2=-\frac{5}{8}\end{cases}}\)