Bob, driving a new ford, travels 330 miles in the same amount of time it takes john, driving an old chevy and traveling 10 miles per hour faster, to travel 390 miles. how fast is bob driving?

  55 mph

Step-by-step explanation:

Let x represent Bob's speed. Then John's speed is x+10, and their respective times are found by ...

  time = distance/speed

  330/x = 390/(x+10) . . . . . . . the times are the same

  330(x +10) = 390x . . . . . . .  multiply by x(x+10)

  3300 = 60x . . . . . . . . . . . . . subtract 330x

  55 = x . . . . . . . . . . . . . . . . . . divide by the coefficient of x

Bob is driving at 55 miles per hour.

pentagon

step-by-step explanation:

the coordinates   a(5, -2), b(3,-1),c(-4,-4) d(-3,8) and e(-1,4) forms the vertices of the polygon when they are connected in order.

in order to classify that which polygon is it with the given coordinates, first count the number of vertices and then count the number of sides it can make with these vertices.

since, the given coordinates have five vertices, therefore, it will make five sides. moreover, pentagon is regular in nature therefore it will be convex.

now, a polygon with five sides is known as pentagon, therefore, the given polygon is the pentagon.