Answer:

Step-by-step explanation:
Please refer to the attachment.
By AA Similarity, the two triangles are similar.
Therefore, corresponding parts of them are proportional.
Therefore, we can write the following proportion:

We will solve for x. Cross-multiply:

Distribute:

Subtract 21 from both sides:

Divide both sides by 7. So, the value of x is:

However, that is only the value of x.
The shadow of the tree is (x+3).
Hence, we will need tot add 3 to our value. Therefore, the actual length of the shadow of the tree is approximately:

Answer:
4 2/3 hours
Step-by-step explanation:
There are 7 days in a week
2/3 of an hour per day * 7 days
2/3 *7 = 14/3 hours
Changing to a mixed number
4 2/3 hours
Answer:
A. -2x^2-2x-2
Step-by-step explanation:
(2x^2-5x-4)-(4x^2-3x-2)
distribute the minus sign
(2x^2-5x-4)-4x^2+3x+2
2x^2-5x-4
-4x^2+3x+2
-------------------------
-2x^2 -2x-2