Answer:
B
Step-by-step explanation:
Yes, it is. The set of rational numbers is closed for all the four operations, so x+y, x-y, x*y and x/y are rational too. And it is easy to demonstrate. A rational number can be expressed as a fraction of two integers. So, x can be expressed as a/b and y as c/d. Hence x+y = a/b + c/d = (ad+bc)/bd, which, as fraction of two integers, is rational.
Answer:
(a) The product of the sum of a and b and their difference.

(b) The tripled product of 6a and b².

(c) The difference of the squares of 2m and 7n.

Answer:
Option D (r(t) = 3.50t +25
; r(8) = 53)
Step-by-step explanation:
The fixed cost to rent the kayak $25. This is the cost which remains fixed irrespective of the usage of the kayak. The variable cost of using the kayak is the cost which depends on the usage of the kayak. It is mentioned that the kayak is used for 4 hours and the company charges $3.5 for every half hour. The cost function is given by:
r(t) = 25 + 3.5t ; there r is the total cost of using the kayak and t is the number of half-hours the kayak is used.
4 hours means that there are 8 half-hours. Therefore, t=8. Put t=8 in r(t).
r(8) = 25 + 3.5*(8) = 25 + 28 = 53.
Therefore, Option D is the correct answer!!!
1.The height is 6 inches ad the width (diameter) is 3 inches!
2. So the jars are Volume ≈ 42.41 inches so each boy needs 200 / 42.41 which equals approximately 4.72 inches per jar. So if wach boys have half the amount of jars which is 20 you multiply 20 by 4.72 which is 94.4 inches for each boy!
X=3,-1 your answer is right here