5x^-2y^140 over 256x^-1(-3x^-34y^-1)^-67

\frac{5x^{-2}y^{140}}{256x^{-1}(-3x^{-34}y^{-1})^{-67}}

This is not an equation, it is an expression.

Equations have equals signs.

What is it you need to do? Simplify?

First, write with positive exponents:

\frac{5y^{140}x(-3x^{-34}y^{-1})^{67}}{256x^{2}}

Power rule of exponents, distribute the 67 through by multiplying it by the exponents inside the parentheses.

\frac{5y^{140}(-3)^{67}x^{-2277}y^{-67}}{256x^{2}}

Add exponents of like bases, 140-67=73

Subtract exponents when dividing, -2277-2=-2279

Make everything positive exponents:

\frac{5\cdot (-3)^{67}y^{73}}{256x^{2279}}