D is the answer
(4+8)+1 = 13
4+(8+1) = 13
Therefore equation D is true
Answer:

Step-by-step explanation:
The length of the base is the distance between the points 4+2i and 10+4i, so

The middle point of the base is placed at point

The length of the height is the distance between the points 5+9i and 7+3i

So, the area of the triangle is

During Distributive property, the number on the outside of the parenthesis basically gets multiplied by the numbers inside the parenthesis. In this case, you would multiply 6 by 5 and 4. When you get the products, then follow the sign that comes next. In this case, you would add the products to get a total sum. I attached a photo for further reference.
Hope this helps!
Answer:
the first one
Step-by-step explanation:
John's effective annual rate is about
(1 +.0576/4)^4 -1 ≈ 5.8856%
According to the "rule of 72", John's money will have doubled in
72/5.8856 = 12.23 years
John's balance will be $4500 in 1989.
_____
Since you're only concerned with the year (not the month), you don't actually need to determine the effective annual rate. The given rate of 5.76% will tell you 72/5.76 = 12.5 years. The actual doubling time is closer to 12.12 years, so using the effective rate gives results that are closer, but "good enough" is good enough in this case.