Answer:
not sure for the 1st one but pretty sure 2nd one is B
Step-by-step explanation:
Answer:
644 cm²
Step-by-step explanation:
Surface area of the composite figure = surface area of the large rectangular prism + surface area of the small rectangular prism - 2(area of the surface of the small rectangular prism that joins the larger prism)
✔️Surface area of the large rectangular prism = 2(LW + LH + WH)
L = 6 cm
W = 5 cm
H = 20 cm
Surface area = 2(6*5 + 6*20 + 5*20)
= 500 cm²
✔️Surface area of the small rectangular prism = 2(LW + LH + WH)
L = 6 cm
W = 4 cm
H = 12 cm
Surface area = 2(6*4 + 6*12 + 4*12)
= 288 cm²
✔️area of the surface of the small rectangular prism that joins the larger prism = L*W
L = 12 cm
W = 6 cm
Area = 12*6
= 72 cm²
✅Surface area of the composite figure = 500 + 288 - 2(72)
= 644 cm²
If is an integer (a whole number), then the expression represents an even number, because even numbers are the multiples of 2. The expressions 2 n − 1 and 2 n + 1 can represent odd numbers, as an odd number is one less, or one more than an even number.
The speed of the airplane is the ratio of the distance to the time
The initial average speed of the airplane is approximately 110.8 mph
Reason:
Given parameters are;
The distance between Portland Oregon and Seattle Washington = 145 miles
The decrease in travel time when the speed is increase by 20 mph = minutes
The initial speed of the airplane, v = Required;
Solution;


Therefore;

Which gives;

Therefore
0.2·v² + 4·v - 2,900 = 0
v ≈ ±110.8 mph
The initial average speed of the airplane, v≈ ± 110.8 mph
Learn more here:
brainly.com/question/11365874
<h3>
Answer: 8a + 7b + 2c</h3>
Work Shown:
(11a - 2b + 7c) - (3a - 9b + 5c)
11a - 2b + 7c - 3a + 9b - 5c ... see note below
(11a-3a) + (-2b+9b) + (7c-5c)
8a + 7b + 2c
note: don't forget to distribute the negative through to every term inside the parenthesis