21. A 3 - t fire hydrant is next to a road sign. The shadow of the fire hydrant is 4.5 ft long. The shadow of the road sign is 12 ft long. The shadows form similar triangles. What is the height in feet of the sign? \( \begin{array}{llll}\text { A) } 1.6875 & \text { (B) } 8 & \text { (C) } 12 & \text { (D) } 16.5\end{array} \)

What is the distance from 4 to 8 on the number line?

28. \( 9 x+5-4 x=-20 \)

1. Triangle \( A B C \) has vertices located at \( A(0,2), B(4,2) \), and \( C(4,4) \). Triangle \( A^{\prime} B^{\prime} C^{\prime} \) is the result of dilating Triangle \( A B C \) using the origin as the center of dilation and a scale factor of 3. Predict the coordinates of Triangle \( A^{\prime} B^{\prime} C^{\prime} \) and record them in the table.

1) Resolvé aplicando la definición de logaritmo. a) \( \log _{3} 81= \) b) \( \log _{2} 64=6 \) c) \( \log _{2} 8= \) d) \( \log _{2} 1000= \) e) \( \log _{6} 216= \) f) \( \log _{2}-4= \)

Since the difference is statistically significant, can we conclude that the vaccine prevents polio? yes no