Respuesta :

The correct answer is 3. x-84=3x

That's because
X/12 - 7 = x/4 is also (x-84)/7 = x/4 and when you cross multiply it you get (x-84)*4 = x * 7
4x-336=7x
-3x = 336
x = 336/-3
x = -112


Answer:

Option 3. [tex]x-84=3x[/tex]

Step-by-step explanation:

we have

[tex]\frac{x}{12}-7=\frac{x}{4}[/tex]

simplify

Multiply by [tex]12[/tex] both sides

[tex]12(\frac{x}{12}-7)=12(\frac{x}{4})[/tex]

[tex]x-7*12=3x\\ \\x-84=3x[/tex]

[tex]3x-x=-84\\ 2x=-84\\ x=-42[/tex]

therefore

the answer is the option 3