GCSE MATHS HELP PLEASE!! ASAP

Can you help me ans this question.....

A car travels for x hours at a speed of (x+2)km/h. if the distance travelled is 15km, write an equation for x and solve it to find the speed of the car.

While your at it,
i have a huge problem on answering these type of questions, can you tell me some advice or tips when asked these questions

Thanks
^^

Start with the definition of speed: distance divided by time. Then plug in what you've got and solve the algebra problem.

Speed = Distance/Time

Distance = 15 km

Time = x hours

Speed = (x + 2) km/h

x + 2 = 15/x

Multiply both sides by x to clear the fraction.

x(x + 2) = 15

Simplify

x^2 + 2x = 15

x^2 + 2x - 15 = 0

Factor using FOIL.

(x + 5)(x - 3) = 0

There are two algebraic solutions for x, but since it stands for time, only the positive solution is relevant.

x = 3 hr.

Go back and solve for speed.

Speed = (x + 2) km/hr.

Speed = 3 + 2 = 5 km/hr

Time*Speed = Distance

X = Time
X + 2 = Speed
Y = Distance

X*(X+2) = Y (Distance)

X^2 + 2x = Y (Distance)

Distance = 15km

so

X^2 + 2x = 15

OR

X^2 + 2x - 15 = 0
(for that quadratic formula i think)

Hopefully this points you in the right direction.