Math question, need working and possibly with a explanation?

Question

a car travels for 2 hours at a certain speed and then three hours more at a speed of 10km/h faster than this. If the entire distance travelled is 455km find the car's speed in the first two hours of travel

Answer 1

Okay, here we go...

You know your answer has to be 455. And you know the car traveled at a speed, so let's call that speed "x". Then, you can set this up as an equation. Here's what you come up with then:

x + x + (x+10) + (x+10) + (x+10) This is what you get because x is the speed that was travelled for 2 hours, so you need two x's. Then, because you add 10km/h to the original speed for 3 hours, you need x+10 three times. Then, simply set it equal to 455.

x + x + (x+10) + (x+10) + (x+10) = 455

COMBINE YOUR X'S AND TENS: 5x + 30 = 455
SUBTRACT 30 FROM BOTH SIDES: 5x + 30 - 30 = 455 - 30
This is what you're left with: 5x = 425
DIVIDE BOTH SIDES BY 5: 5x/5 = 425/5
This is what you're left with: x = 85

Now, because "x" is the original speed, your answer for the first two hours of travel is simply 85km/h.

You're Welcome.
Best Wishes.

Answer 2

OK, what we have is a compound distance problem. You can work through these by figuring out an equation, plugging in what you know, and then solving the equation.
The general equation for distance is:
D=RT
where D is distance traveled, R is rate (speed) of travel, and T is travel time. But here, we have two different rates (R' and R'') and two travel times (T' and T''); and the total distance traveled. Since the total distance traveled (D) is the same as the distance traveled going the first speed (we'll call it D') and the distance at the second speed (D''), we can go from there...
D = D'+D''
D' = R' x T'
D'' = R'' x T''
Let's simplify it into one equation by substituting back...
D = (R'T') + (R"T")
And then we plug in the numbers, using a variable (x) for our initial speed.
455 = (2x) + 3(x+10)
455 = 2x + 3x + 30
455 = 5x + 30
425 = 5x
85 = x
So, the speed in the first two hours of travel (x) is 85 km/h. The check is left to you.

Answer 3

let v be the speed of the car at a certain distance for two hours. At the end of 2hrs, the speed of the car is v + 10

the distance the car goes in 2hrs plus the distance the car goes in 3hrs equal 445km

x = vt
2v + (v+10)3 = 455
2v + 3v + 30 = 455
5v = 415
v = 85 km/hr

Answer 4

CAN BE EXPRESSED AS:

2x + 3(x + 10) = 455

WHERE x, IS THE VARIABLE FOR km/hr

CAN BE SIMPLIFIED TO:

5x + 30 = 455
5x = 455 - 30
5x = 425
5x/5 = 425/5
x = 85

THEREFORE, the car traveled 85 km/hr on the first 2 hours of travel covering 170 kms.

Answer 5

Let the speed in the 1st 2hrs be y.
Let the speed after the 1st 2hrs be (y+10)km/h

Distance travelled in the 1st two hours = 2hrs x y km/h = 2y km
Distance travelled in the subsequent 3hours = 3 x (y+10)km/h = (3y + 30)km
Total distance travelled = (3y + 30) + 2y = 5y + 30
Therefore 5y+30 = 455
5y=425
y=85km/h

Answer 6

First, make this into an equation:

2 hours at one rate
3 at another (10 km/h faster)
total = 455 km

So:

2x + 3(x+10) = 455

Then, just solve for x:

2x + 3x + 30 = 455

2x + 3x = 425

5x = 425

x = 85

So your answer is 85 km/h for the first two hours and 95 km/h for the last three.

Hope this helps!

Answer 7

let first speed =x km/hr
so, distance travelled in 2hours=2xkm

let next speed=x+10
so, distance travelled in 3hours=3(x+10)

so, total distance=2x+3(x+10)=5x+30

here 5x+30=455
or x=425/5=85km/hour

Answer 8

2x+3(x+10)=455
2x+3x+30=455
2x+3x=425
5x=425
x=85

"x" represents the speed per hour for the first two hours. "x+10" represents the speed per hour for the final three hours.

Answer 9

x=85

2x + 3(x+10) = 455km
5x+30=455
5x=425

x=85 km/h
x+10=95 km/hy

Answer 10

there isn't any actual selection whose sq. is damaging. The "imaginary" selection sqrt(-one million) = i has the valuables i^2 = -- one million. additionally (-i)^2 = -- one million. sqrt(--sixteen) = sqrt((sixteen)(-one million)) = 4 sqrt(- one million) = 4i (or -- 4i) Numbers like 2 + 5i are referred to as "complicated numbers" they're elevated making use of the rule of thumb i^2 = -one million. 2 + 5i corresponds to the factor (2,5) interior the plane, basically as actual numbers correspond to factors on a line.