math problem?

Question

A. susan's father is 3 years more than twice as old as susan . the product of their ages in years is 560. how old is susan?
in this problem, is my translation of the unknowns correct?
2x(x+3)=560?
B. the metro rail travels 240km at a uniform rate.if the speed had been 8 km per hour , the journey would have taken 1 hour less.what is the speed of the train?
is this correct? 8x(x-1)=240?
C. joel drives his car for 20 km at a certain speed . at a distance, he increases his speed by 5 km per hour and drives for an additional 20 km. if the total trip takenis 1 hour, what is his original speed?

CORRECTION;
8 KM PER HOUR MORE.

Answer 1

A)
susan's age = x
susan's father's age = twice of x + 3 => 2x+3
so x * (2x+3) = 560
and further there is no need to find a quadratic equation always,
560 = 10*56 or 16 * 35 or 20 * 28....
the solution is 16 and 35

B)
actual speed be v and time be t
if speed is increased by 8 time is t-1
since distance same,
v * t = (v+8)*(t-1) = 240
Hence simply factorize 240 satisfying the above condition,
240 = 40*6 or 48*5 so v is 40 km/hr


C)
speed for first 20km be v and speed for next 20km is v+5
time for first 20km is 20/v and for next 20km is 20/v+5

hence 20/v + 20/(v+5) = 1
then solve for v

Answer 2

A) No s = susans age : 2s + 3 is the age of her father. s*(2s +3)=560

B) at 8 km/h 240 kmtake 240/8 = 30 hours, with the real speed it will take 31 hours thus the speed is 240/31 km/h

c) o urslef my head hurts

time of first part : 20/x
time of second part 20/(x+5)
20/x + 20/(x+5) = 1 => x is the original speed

Answer 3

A: x = susan's age
father's age = 2x + 3
(2x+3) * x = 560 = 2x^2 + 3x

B: 240km / 8kph = 30 hours
240km / x = 31 hours
speed of train = 240 / 31

C: distance / speed = time

(20km / x) + (20km / (x + 5kph) = 1 hour

(20 * (x + 5)) + (20 * x)
----------------------------- = 1
(x + 5) * x

20x + 100 + 20x
--------------------- = 1
x^2 + 5x

40x + 100
------------ = 1
x^2 + 5x

40x + 100 = x^2 + 5x

x^2 - 35x = 100

now solve using quadratic formula

Answer 4

I think:
A. x(2x+3)=560
B. 8(x-1)=240
C. 1=20/x+20/(x+5)

THEN CORRECTION OF B:
240/x-240/(x+8)=1

Answer 5

A: x(2x + 3) = 560

B: (240/8) = (240/x) - 1

C: (20/x) + (20/(x+5)) = 1

Answer 6

i think I'm going to take a tablet and go to bed bye

Answer 7

Do you intend to do any of your own homework?