Evaluate the expression when a=7 and c=-2.
a-4c

Agraph of a trapezoid can have diagonals with slopes that are negative reciprocals and two pairs of adjacent sides that are congruent, true or false, and why

Me, the vertices of quadrilateral coat are c(2,0), o(7,0), a(7,2) and t(2,2). prove that coat is a rectangle.

Which steps could be part of the process in algebraically solving the system of equations, y+5x=x^2+10 and y=4x-10