Question

Tìm x biết

\(\dfrac{2x+3}{4x-7}=\dfrac{5}{4}\)

Answer 1

từ đảng thức trên, ta suy ra:

2x+3.4=4x-7.5

<=> 2x+12=4x-35

<=> 35+12=4x-2x

<=> 47=2x

=>x=47:2=23,5

Answer 2

Ta có: \(\dfrac{2x+3}{4x-7}=\dfrac{5}{4}\) \(\Rightarrow\left(2x-3\right)4=\left(4x-7\right)5\)

\(\Rightarrow8x+12=20x-35\)

\(\Rightarrow8x-20x=-35-12\)

\(\Rightarrow-12x=-47\Rightarrow x=\dfrac{47}{12}\)

Answer 3

Ta có: 2x + 3 / 4x - 7 = 5/4

=> 4(2x+3) = 5(4x-7)

8x + 12 = 20x -35

12 + 35 = 20x - 8x

47 = 12x

x = 47/12