Answer:
the rate of each train is 139 km/h and 159 km/h.
Step-by-step explanation:
let
v = the rate of the slower train
v + 20 = the rate of the faster train
d = 1490 km the distance that the two train will travel
t = 5 hr the time of the travel
since speed = distance/time => distance = speed*time
v*t + (v+20)t = d
5v + 5(v + 20) = 1490
5v+5(v+20)=1490
Step 1: Simplify both sides of the equation.
5v+5(v+20)=1490
5v+(5)(v)+(5)(20)=1490(Distribute)
5v+5v+100=1490
(5v+5v)+(100)=1490(Combine Like Terms)
10v+100=1490
10v+100=1490
Step 2: Subtract 100 from both sides.
10v+100−100=1490−100
10v=1390
Step 3: Divide both sides by 10.
10v/10 = 1390/10
v = 139km/h
Next
we add 139 to 20
139 + 20 = 159 km/h
the rate of each train is 139 km/h and 159 km/h.
Mean the the total of all values, divided by the number of values
X = 2a - b²
x - 2a = b²
√x-2a = b
Just to clarify, all of x-2a is under the square root.
Answer:
(7 x + 6 y)^2
Step-by-step explanation:
Factor the following:
49 x^2 + 84 x y + 36 y^2
The coefficient of x^2 is 49 and the coefficient of y^2 is 36. The product of 49 and 36 is 1764. The factors of 1764 which sum to 84 are 42 and 42. So 49 x^2 + 84 x y + 36 y^2 = 49 x^2 + 42 x y + 42 x y + 36 y^2 = 7 x (7 x + 6 y) + 6 y (7 x + 6 y):
7 x (7 x + 6 y) + 6 y (7 x + 6 y)
Factor 7 x + 6 y from 7 x (7 x + 6 y) + 6 y (7 x + 6 y):
(7 x + 6 y) (7 x + 6 y)
(7 x + 6 y) (7 x + 6 y) = (7 x + 6 y)^2:
Answer: (7 x + 6 y)^2
Answer:
one quarter of the total number of students will be those who failed their exam.
Step-by-step explanation:
Three - fourths = those who passed the exam
one quarter will be those who failed their exam
From the total number of the students.
Let's make an example
40 students who take the exam.
3 over 4 students from the total number of 40 take the exam and the result is passed and it mean 30 students passed in the exam.
1 over 4 students take the exam and the result is failed and it mean 10 students failed in the exam.
4 minus 3 over 4 will get the answer 1 over 4.
Use 1 over 4 to multiple with the total number of the students and that how you will get the answer for those who failed in their exam.
