Question

If you answer my question I will follow you . Sum is from lesson quadratic equation please answer it early ​

Answer 1

Answer:

40kmph

Step-by-step explanation:

Let the speed of the train be x

Then,

t=d/v

t=480/x------1

Now speed is x-8,according to question

Now

t+3=480/x-8(according to question)

So t=(480/x-8)-3 - - - -2

Equate 1 and 2 and find x

Hope it helps

Answer 2

Answer:

40 Km/hr

Step-by-step explanation:

Let the original speed be x Km/hr

and time taken be t hr

$480 = x \times t$

Also given

$480 = (x - 8) \times (t + </strong><strong>3</strong><strong>)$

$480 = (x - 8)( \frac{480}{x} + </strong><strong>3</strong><strong>)$

$480 = 480 + </strong><strong>3</strong><strong>x - \frac{3840}{x} - </strong><strong>2</strong><strong>4</strong><strong>$

$</strong><strong>3</strong><strong>{x}^{2} - </strong><strong>2</strong><strong>4</strong><strong>x - 3840 = 0$

${x}^{2} - 8x -1280 = 0$

$(x - 40)(x + 32) = 0$

$x = 4p$

or

x=-32 (Not Possible)