Answer:
The cost of the diamond last year is x = $ 830
Step-by-step explanation:
Let the cost of diamond last year = x
the cost of diamond present year = y
Given that diamond today cost ten dollars more than twice what it cost last year.
⇒ y = 2 x + 10 ------ (1)
The sum of the cost (last year and this year) is = $ 2500
⇒ x + y = $ 2500 -------- (2)
Put the value of y in equation (2) from equation (1), we get
⇒ 2 x + 10 + x = $ 2500
⇒ 3 x = 2490
⇒ x = $ 830
& y = 2500 - 830
⇒ y = $ 1670
Therefore the cost of the diamond last year is x = $ 830
Selections B and D both appear to be appropriate.
B) (x+8)² + (y+5)² = 13
D) (x+8)² + (y+5)² = 13
_____
The center is at the midpoint of the diameter, ((-10-6)/2, (-8-2)/2) = (-8, -5). For center (h, k) and radius r, the equation is
(x -h)² +(y -k)² = r²
(x -(-8))² +(y -(-5))² = (√13)²
(x+8)² + (y+5)² = 13
Answer: -1.6 is not a possible r-value.
Step-by-step explanation:
R-values range from -1 to +1. Out of all these numbers, -1.6 does not belong. Hence, -1.6 is not a r-value.
Answer: B
Step-by-step explanation:
Both the mean and the median will decrease, but the mean will decrease by more than the median.