a father was 25 years older than his son five years ago. if the product of the son and his father's ages then was 900 years. how old is the son now.

  25

Step-by-step explanation:

Let x represent the son's age now. 5 years ago, it was x-5, and the father's age was (x -5)+25 = (x+20).

The product of their ages at that time was 900, so we have ...

  (x -5)(x +20) = 900

  x^2 +15x -100 = 900

  x^2 +15x -1000 = 0 . . . . subtract 900

  (x +40)(x -25) = 0 . . . . factor

  x = -40 or +25 . . . . these values make the factors zero

The son's age now is 25.

560

hope this : )

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."