Answer:
52/3
Step-by-step explanation:
Use basic Thales therom,
[tex]\frac{3x}{4x}=\frac{3x+7}{5x-8}\\\\\frac{3}{4}=\frac{3x+7}{5x-8}\\[/tex]
Cross multiply,
3*(5x-8)=4*(3x+7)
3*5x - 3*8 = 4*3x + 4*7
15x - 24 = 12x +28
Add 24 to both sides
15x = 12x + 28 + 24
15x = 12x + 52
Subtract 12x from both sides
15x-12x =52
3x = 52
Divide both sides by 3
x = 52/3