Kiran starts at 9:00 am by bicycle to reach office. She cycles at the speed of 8 km/hour and reaches the office at 9:15 am. By how much should she increase the speed so that she can reach the office at 9:10 am?

Step-by-step explanation:

Given  data

speed = 8km/h

time taken= 9 am- 9:15 am = 15 mins

convert 15 mins to hours= 1/60*15 = 0.25 hrs

we can now calculate the distance

speed= distance/time

8= d/0.25

d= 8*0.25

d= 2km

now for Kiran to arrive in 10min (0.16 hrs), since the distance is 2 km

let us find the speed

speed= d/t

speed= 2/0.166

speed= 12.0km/h

Hence she needs to increase her speed by 12-8= 4km/h

step-by-step explanation:

equation

you are asked to write the equation

  expression = 0

using the given expression. when you do that, you have

  2x^2-2x-12 = 0

factoring

you can see that each of the coefficients is even, so a factor of 2 can be removed immediately.

  2(x^2 -x -6) = 0

if you multiply the binomials (x+a)(x+b), you get

  (x +a)(x +b) = x^2 +(a+b)x +ab

this tells you the coefficient of x is the sum of two factors of the constant term. here, that means -1 is the sum of two factors of -6. we want to know those factors so we can factor the trinomial.

  -6 = -1×6 = -2×3 = -3×2 = -6×1

the factor pair that sums to -1 is {-3, 2}, so our factorization is

  2(x -3)(x +2) = 0

solutions

the solutions to this equation are the values of x that make the product zero. a product is zero only when only of the factors of the product is zero. here, that means

  x - 3 = 0

  x = 3 . . . add 3 to both sides of the equation

or

  x +2 = 0

  x = -2 . . . add -2 to both sides of the equation

the solutions to the equation are x=3 or x=-2. both of these values of x satisfy the equation—they make it be true.