- 4 w - 4 = - 24
- 4w = - 20
w = 5
Answer:
<em>The SUV is running at 70 km/h</em>
Step-by-step explanation:
<u>Speed As Rate Of Change
</u>
The speed can be understood as the rate of change of the distance in time. When the distance increases with time, the speed is positive and vice-versa. The instantaneous rate of change of the distance allows us to find the speed as a function of time.
This is the situation. A police car is 0.6 Km above the intersection and is approaching it at 60 km/h. Since the distance is decreasing, this speed is negative. On the other side, the SUV is 0.8 km east of intersection running from the police. The distance is increasing, so the speed should be positive. The distance traveled by the police car (y) and the distance traveled by the SUV (x) form a right triangle whose hypotenuse is the distance between them (d). We have:

To find the instant speeds, we need to compute the derivative of d respect to the time (t). Since d,x, and y depend on time, we apply the chain rule as follows:

Where x' is the speed of the SUV and y' is the speed of the police car (y'=-60 km/h)
We'll compute :


We know d'=20 km/h, so we can solve for x' and find the speed of the SUV

Thus we have

Solving for x'

Since y'=-60


The SUV is running at 70 km/h
Answer:
450 ounces
Step-by-step explanation:
We know that the cost of the mixture
must be the cost of the everyday moisturizing lotion
plus the cost of the self-tanning lotion
, which means
.
The cost of any substance will be the cost per ounce of the substance (c), multiplied by the number of ounces (n), which means C=nc, so we have from the previous formula that we have:

But we also know that the number of ounces of the mixture must be the sum of the number of ounces of the everyday moisturizing lotion with the number of ounces of the self-tanning lotion, so we have

We want to calculate the number of ounces of the self-tanning lotion (
), so we solve for that variable:




And substitute our values in this formula, to get:
