Answer:
Step-by-step explanation:
From the given information:
There are 30 collections of gems, of which 8 are worthless;
Thus, the number of the genuine diamonds = 30 - 8 = 22.
Let X = random variable;
X consider the value as 0 (for 2 worthless stone selection),
X = 1200(1 worthless stone & 1 genuine stone)
X = 2400 (2 genuine stones selected)
However, the numbers of ways of selecting and chosen Gems can be estimated as:

Thus;








To find E(X):
E(X) = (0 × 0.0644) + (1200 × 0.4046) + (2400 × 0.5310)
E(X) = 0 + 485.52 + 1274.4
E(X) = 1759.92
(x^2) - 16 / x+4 = (x-4)(x+4) / (x+4) = x-4, x not equal to -4
D is the answer.
Substitution doesn't work for this, but elimination does.
-6x-8y=-20 +6( x+6y=-6)
-6x-8y=-20 + 6x+36y=-36
-6x and 6x cancel each other, add -8 and 36 to get 28, and -20 and -36 to get -56.
28y=-56
divide by 28 on both sides.
Y= -2
Then substitute y into one of the equations.
x+6(-2)=-6
x-12=-6
x=6
The ordered pair is (6,-2).
C is the correct answer. A line is proportional if it is a straight line that passes through the origin, and while it does pass through the origin, it isn’t completely straight.
2x + y = 10
5x - y = 18
7x = 28
x = 4
2(4) + y = 10
8 + y = 10
y = 2
(4,2)