What is the value of the variable is

Petes dog weighed 30 pounds it then lost 16% of it's weight how much did pete lose

One file clerk can file 10 folders per minute. a second file clerk can file 11 folders per minute. how many minutes would the two clerks together take to file 672 folders?

Find the vertex for the parabola given by the function ƒ(x) = −3x2 − 6x.