Determine which system will produce infinitely many solutions. −4x + 6y = 20
4x − 3y = −2

−2x + 4y = 18
4x − 8y = −36

3x − 2y = 5
−6x − 4y = −10

5x − 3y = 12
15x − 9y = 24

Asphere has a diameter of 10 in. what is the volume of the sphere?

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

Every weekday, mr. jones bikes from his home to his job. sometimes he rides along two roads, the long route that is shown by the solid lines. other times, he takes the shortcut shown by the dashed line. how many fewer kilometers does mr. jones bike when he takes the shortcut instead of the long route?