Answer:
7 : 1
Step-by-step explanation:
Paul's car goes 40 kilometers on 7 tanks.
Distance : Tanks
49 : 7
Fuel efficiency means the distance traveled by the car in one tank.
Therefore, we will reduce the ratio by dividing both sides by 7.
Distance : Tanks
: 
7 : 1
Therefore, car's fuel efficiency is 7 kilometers in one tank or the ratio between Distance traveled and fuel tanks is 7 : 1.
Answer:
A
Step-by-step explanation:
We know that in normal distribution, approximately 34% of bags will fall with in one standard deviation on one side. On both sides within the range of 1 standard deviation, 34 + 34 = 68 % of bags will fall.
Our range is:
1600 to 1620
1610 - 10 to 1610 + 10
So the answer is 1
That means, that 68% is the answer.
25.59- 9.99= 15.60
15.60/ 0.05 = 312
312 minutes this month
Where the pic or question?
x*y' + y = 8x
y' + y/x = 8 .... divide everything by x
dy/dx + y/x = 8
dy/dx + (1/x)*y = 8
We have something in the form
y' + P(x)*y = Q(x)
which is a first order ODE
The integrating factor is 
Multiply both sides by the integrating factor (x) and we get the following:
dy/dx + (1/x)*y = 8
x*dy/dx + x*(1/x)*y = x*8
x*dy/dx + y = 8x
y + x*dy/dx = 8x
Note the left hand side is the result of using the product rule on xy. We technically didn't need the integrating factor since we already had the original equation in this format, but I wanted to use it anyway (since other ODE problems may not be as simple).
Since (xy)' turns into y + x*dy/dx, and vice versa, this means
y + x*dy/dx = 8x turns into (xy)' = 8x
Integrating both sides with respect to x leads to
xy = 4x^2 + C
y = (4x^2 + C)/x
y = (4x^2)/x + C/x
y = 4x + Cx^(-1)
where C is a constant. In this case, C = -5 leads to a solution
y = 4x - 5x^(-1)
you can check this answer by deriving both sides with respect to x
dy/dx = 4 + 5x^(-2)
Then plugging this along with y = 4x - 5x^(-1) into the ODE given, and you should find it satisfies that equation.