Number of multiples of 7 between 200 and 1000

The border line of the linear inequality 4x + 7y < 5 is dotted true or false?

In right ∆abc shown below, the midpoint of hypotenuse ac is located at d and segment bd is drawn.if ab = 12 and bc = 16, then explain why bd = 10. hint: consider what you know about the diagonals of a rectangle.

Can someone me out here number 4 plz