9. \( -4 \cdot 9+-4 \cdot 11=-4( \)

To solve the equation \( -4 \cdot 9 + -4 \cdot 11 = -4( \), we can factor out \(-4\) from both terms on the left side. This gives us: \[ -4(9 + 11) = -4(20) = -80. \] So the simplified equation results in \( -80 \). Factoring out common terms not only simplifies calculations but also highlights important underlying relationships in math! Additionally, this technique of factoring is especially handy when dealing with larger equations or polynomials. Remember that grouping like terms can make complex problems much more approachable, making your math journey smoother and more enjoyable!