Write an expression for the calculation double the product of 4 and 7

The line containing the midpoints of the legs of right triangle abc where a(-5,5), b(1, 1), and c(3, 4) are the vertices.

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

The tile along the edge of a triangular community pool needs to be replaced? ?