Answer:
System of equations:
20x + 30y = 650
x + y = 25
Time underwater = 10 hours
Time at the surface = 15 hours
Step-by-step explanation:
Let x = time underwater at 20 km/h.
Let y = time on the surface at 30 km/h.
speed = distance/time
distance = speed * time
distance underwater: 20x
distance on the surface: 30y
total distance: 650
20x + 30y = 650
total time: x + y
total time: 25
x + y = 25
20x + 30y = 650
x + y = 25
20x + 30y = 650
-20x - 20y = -500
--------------------------------
10y = 150
y = 15
x + y = 25
x + 15 = 25
x = 10
Answer:
b
Step-by-step explanation:
1. 2r-5
2. -21r-50
3. 4r-50
4. 14r+50
5. 19r-50
Answer:
The inverse of xy is yx.
Step-by-step explanation:
Given: xy
We need to find the inverse of xy.
To find inverse of an expression, we need to replace the variable x by y and y by x.
Given xy.
Now replace x by y and y by x, we get
yx
Therefore, the inverse of xy is yx.
Let me show you an example.
y = x - 2
To find the inverse function, replace x by y and y by x, we get
x = y - 2
It is an equation, to write the equation in terms of y, add 2 from both sides, we get
x + 2 = y -2 + 2
x + 2 = y
Therefore, y = x + 2
Answer:
5
Step-by-step explanation:
= 3.87
= 8.25
Integers between the two:
4, 5, 6, 7, 8
5 numbers in total