How can we tell that 4:1 and 12:3 are equivalent ratios?

How many different ways can you make change for $.50 using only nickels, dimes, and quarters?

Two rigid transformations are used to map abc to qrs. the first is a translation of vertex b to vertex r. what is the second transformation? a reflection across the line containing ab a rotation about point b a reflection across the line containing cb a rotation about point c

Indicate the formula for the following conditions: p^c(n, r)=