Respuesta :

[tex]\\ \sf\longmapsto \dfrac{5x+3}{7x+3}=\dfrac{3}{4}[/tex]

[tex]\\ \sf\longmapsto 4(5x+3)=3(7x+3)[/tex]

[tex]\\ \sf\longmapsto 20x+12=21x+9[/tex]

[tex]\\ \sf\longmapsto 12-9=21x-20x[/tex]

[tex]\\ \sf\longmapsto x=3[/tex]

[tex]\large\rm \longrightarrow \: {\purple{ \frac{(5x + 3)}{(7x + 3)} \: = \: \frac{3}{4} }} \\ [/tex]

Now , Cross Multiplying

[tex]\large\rm \longrightarrow \: {\blue{ 4 \: (5x + 3) \: = \: 3 \: (7x + 3)}}[/tex]

[tex]\large\rm \longrightarrow \: {\red{ 20x \: + \: 3 \: = \: 21 \: + \: 3}}[/tex]

[tex]\large\rm \longrightarrow \: {\orange{ 12 \: - \: 9 \: = \: 21x \: - \: 20x }}[/tex]

[tex]\large\rm \longrightarrow \:{\green{ 3 \: = \: x}}[/tex]

Hence , the value of x is 3