Speed of the car is 45 km/h
Step-by-step explanation:
- Step 1: Find the distance traveled by the car in the first case.
Given that the speed of the car = 10 (t + 3) km/h
Time taken = 4 (t + 3) hours
Distance = Speed × Time
= 10 (t + 3) × 4 (t + 3) = 40(t + 3)² km
- Step 2: Equate the distance of 810 km with the distance that has been calculated above, since both are the same.
⇒ 810 = 40 (t + 3)²
⇒ (t + 3)² = 81/4
⇒ t + 3 = √81/4 = 9/2
⇒ t = 9/2 - 3 = 3/2 = 1.5
- Step 3: Find the speed of the car.
Speed = 10 (1.5 + 3) = 10 × 4.5 = 45 km/h
Answer:
50%
Step-by-step explanation:
if there are 2 sets of 7 marbles each part is worth 50% (them put together is 100%). Therefore you have a 50% chance of getting a red marble
Answer:
t = 5 seconds
Step-by-step explanation:
We have,
Speed of the truck, v = 4 m/s
It is required to find the time taken by a truck to travel 20 meters. It can be assumed that the time is t. Using the formula of speed.
After rearranging, we get :
So, the time taken by a truck to travel 20 meters is 5 seconds.
<span>(5+2b)+(7b-5)= 9b
hope it helps</span>
Answer:
A
Step-by-step explanation:
Use foil to expand it.
y = 4 (x^2 + 7x - 9x - 63) Combine the like terms on the right.
y = 4(x^2 - 2x - 63) Use the distributive property to remove the brackets.
y = 4x^2 - 8x - 4*63 Combine the two multiplied factors on the right.
y = 4x^2 - 8x - 252 4* 63 = 252
The answer is A