2x+y=40kx+2y=80 A system of equations is shown, where k is a constant. If the lines represented by the equations in the system are graphed in the xy -plane, for what value of k would the lines coincide?

A- -4
B- 1
C- 2
D- 4

Find the radius of a circle that has a circumference of 16. the formula for the circumference of a circle is c = 2tr, where r is the radius and c is the circumference. the equation solved for r is r = c over 2π. r=4 r= 8 r=12 r= 16