Answer:
Step-by-step explanation:
Let the speed of the car is c and speed of the plane is p.
<h3>We are given:</h3>
The speed of the plane is 7 times the speed of the car
The distance traveled is
The time difference to travel this same distance is 3 hours.
<h3>We know that:</h3>
- d = ts, where d- distance, t- time, s - speed
Find the time for car and plane and their difference.
<h3>Car</h3>
<h3 /><h3>Plane</h3>
- t = d/s = 315/p = 315/(7c) = 35/c
<h3 /><h3>The difference</h3>
<u>Solve it for c:</u>
- (315 - 45)/c = 3
- 270/c = 3
- c = 270/3
- c = 90 km/h
Now find the speed of plane:
As we see, Jenny is right
Answer:
72
Step-by-step explanation:
Answer:
19
Step-by-step explanation:
X will refer to the number.
X+57( the number added to the original.)=4x. (x time 4)
X+57=4x.
Subtract x from both sides to get the variable on one side.
(X+57)-x =(4x)-x
57=3x. You would then divide by 3 on both sides to again get integer isolated.
57/3=3/3x.
57/3=19. 3/3=1.
19=x.
Answer:
21+35
Step-by-step explanation:
use distributive property, multiply 7 by the two numbers in the parenthesis
keep the problem though.
Answer:
The root is x = -2
Step-by-step explanation:
1. Add 4 on both sides.
x^2 + 4r + 4 = 0
2. What two numbers, if added together and multiplied together, give 4?
2 and 2.
3. Factor
(x+2)(x+2)=0
4. Solve
x = -2 (There is only one root for this quadratic equation.)
Please give me brainliest is this is right. Than you!