Problema Solution
a car travels for x hours at a speed of (x+2)km/h.If the distance travelled is 15km, write down an equation for x and solve it to find the speed of the car
Answer provided by our tutors
Here,
Time = X hours
Speed = (x+2)km/h
So, Distance = X* (X+2)
So, the required equation to solve it to find the speed of the car is as follows.
15 = X* (X+2)
Or, 15 = X2+ 2X
Or, X2+ 2X -15 =0
Or, X2+ 5X -3X-15 =0
OR, X(X+5)- 3(X+5) = 0
Or, (X-3) (X+5) =0
So, X = 3, -5
But as speed cannot be negative so X will be 3.
Now, Speed = (x+2)km/h
= (3+2)km/h
= 5 km/h