Answer:
X=51/7, Y= -36/7
Step-by-step explanation:
X/3 + 2y/3 = -1 equ 1
X - y/3 = 9 equ 2
eliminate X/3.
X/3 + 2y/3 = -1..... x 1 ( co-efficient of X in equ2 )
X - y/3 = 9 ...... x 1/3 ( co-efficient of X in equ1 )
X/3 + 2y/3 = - 1 equ 3
-
X/3 - y/9 = 3 equ 4
0 + 7y/9 = -4
y = -36/7
( input the value of y into equ 4 )
X/3 -y/9 = 3
X/3 - (-36/7)/9 = 3
X/3 + 36/63 = 3
X/3 = 3 - 36/63
X/3 = 153/63
63X = 459
X = 459/63
X = 51/7.
Answer:
a)

For any integer k between 0 and 15, and 0 for other values of k.
b)

c) P(6 ≤ X ≤ 10) = 0.2737
d) μ = 15*0.75 = 11.25. σ² = 11.25*0.25 = 2.8125
Step-by-step explanation:
X is a binomial random variable with parameters n = 15, p = 0.75. Therefore
a)

For any integer k between 0 and 15, and 0 for other values of k.
b)
P(X>10) = P(X=11) + P(X=12)+ P(X=13)+P(X=14)+P(x=15)





Thus,

c) P(6 ≤ X ≤ 10) = P(X = 6) + P(X = 7) + P(X = 8) + P(X=9) + P(X=10)





Thereofre,

d) μ = n*p = 15*0.75 = 11.25
σ² = np(1-p) = 11.25*0.25 = 2.8125
Use "PEMDAS" (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction) to know what to do first.
(15 + 6)^{2} - (8 - 5)^{2} Solve the insides of the parentheses
21^{2} - 3^{2} Solve the exponents (21 x 21) and (3 x 3)
441 - 9 Subtract
432
Answer:
a
Step-by-step explanation:
math