(7a-b+3)-(-2a-8b+8)
Apply plus/minus rule.
-(-a)= a and -(a)=-a
we get
(7a-b+3)-(-2a-8b+8)= 7a-b+3+2a+8b-8
Add like terms
=9a+7b-5
Answer: 9a + 7b - 5
Answer:
a) 0.125
b) 7
c) 0.875 hr
d) 1 hr
e) 0.875
Step-by-step explanation:l
Given:
Arrival rate, λ = 7
Service rate, μ = 8
a) probability that no requests for assistance are in the system (system is idle).
Let's first find p.
a) ρ = λ/μ
Probability that the system is idle =
1 - p
= 1 - 0.875
=0.125
probability that no requests for assistance are in the system is 0.125
b) average number of requests that will be waiting for service will be given as:
λ/(μ - λ)
= 7
(c) Average time in minutes before service
= λ/[μ(μ - λ)]
= 0.875 hour
(d) average time at the reference desk in minutes.
Average time in the system js given as: 1/(μ - λ)
= 1 hour
(e) Probability that a new arrival has to wait for service will be:
λ/μ =
= 0.875
Answer:
The area of a rectangle is 520 square inches. The length is 3 more than twice the width. The equation 520 = 2w2 + 3w can be used to find the length and width of the rectangle.
Step-by-step explanation:
1st statement:
l= 2w+3
A= l × w
520= w×(2w+3)
520= 2w²+ 3w
2nd statement:
length of fencing= w+2l
120= w+2l
l= 60-w/2
A= (60-w/2) × w
A= 60w- w²/2
Hence this statement is incorrect
3rd statement:
H= x
B= x-4
P= x-2
Accoriding to pythagoras theorem
H²=P²+B²
x²=(x-4)²+(x-2)²
x²= x²-8x+16 + x²-4x+4
0= x²-12x+20
Hence this statement is incorrect
4th statement:
two consecutive even numbers are given by n and n+2
So this statement is incorrect
Width = w
Length = 2.5w
Area of Rectangle: Width × Length
w (2.5w) = 2250
2.5w^2 = 2250
w^2 = 2250/2.5 = 900
w = Sq rt of 900 = 30
l = 75
Ratio of inches to ft
x/30 = 160/2250
cross multiply: 2250x = 160 × 30
2250x = 4800
x = 4800/2250 = 2.13333...
length
x/75=160/2250
2250x = 75(160)
2250x = 12,000
x= 12,000/2250
x = 5.3333...
scale is 2.13" × 5.33"
Hello,
With
y=x²-4x-21
y=-5x-22
==>x²-4x-21=-5x-22
==>x²+x+1=0
In R, no solution for Δ=1-4=-3<0
