15*0.65= $9.75 is the sale price
Answer:
The area of the rectangle is increasing at a rate of 84 square centimeters per second.
Step-by-step explanation:
The area for a rectangle is given by the formula:

Where <em>w</em> is the width and <em>l</em> is the length.
We are given that the length of the rectangle is increasing at a rate of 6 cm/s and that the width is increasing at a rate of 5 cm/s. In other words, dl/dt = 6 and dw/dt = 5.
First, differentiate the equation with respect to <em>t</em>, where <em>w</em> and <em>l</em> are both functions of <em>t: </em>
![\displaystyle \frac{dA}{dt}=\frac{d}{dt}\left[w\ell]](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cfrac%7BdA%7D%7Bdt%7D%3D%5Cfrac%7Bd%7D%7Bdt%7D%5Cleft%5Bw%5Cell%5D)
By the Product Rule:

Since we know that dl/dt = 6 and that dw/dt = 5:

We want to find the rate at which the area is increasing when the length is 12 cm and the width is 4 cm. Substitute:

The area of the rectangle is increasing at a rate of 84 square centimeters per second.
Answer:
-2.6
Step-by-step explanation:
10.9 + (-15.6) becomes 10.9 - 15.6 which equals -4.7. The last step is to add the 2.1 to the -4.7: -4.7 + 2.1 = -2.6
Therefore the answer is -2.6
Y=3x + 8.25
...................
Given:
Triangles FRI and DAY are similar.
To find:
Similarity ratio
Solution:
<em>If two triangles are similar then the corresponding angles are congruent and the corresponding sides are in proportion.</em>
Here, FR and DA are corresponding sides.

Cancel the common factors of 4 and 6, we get

⇒ FR : DA = 2 : 3
⇒ ΔFRI : ΔDAY = 2 : 3
Similarity ratio of the first triangle to the second triangle is 2 : 3.