# A cable provider wants to contact customers in a particular telephone exchange to see how satisfied

###### Question:

## Answers

1/2x^2=450 20 characters

The correct description is (C). the product of a number and 45.

Step-by-step explanation: We are given to select the correct description that matches the algebraic expression 45n.

Let, 'n' be a number.

Then, the sum of 'n' and 45 is written as (45 + n).

So, option (A) is incorrect.

The quotient of 'n' and 45 is given by [tex]\dfrac{n}{45}~\textup{or}~\dfrac{45}{n}.[/tex]

So, option (B) is incorrect.

The product of 'n' and 45 is

45 × n = 45n, which means 45 times of a number 'n' or n times of 45.

So, option (C) is correct.

The difference of 'n' and 45 is (n - 45) or (45 - n), according as 'n' is greater or 45 is greater.

So, option (D) is incorrect.

Thus, the correct option is (C).

1/2 x^2 = 450

Step-by-step explanation:

x is the greater number.

The other number is 1/2x.

1/2x * x = 450

1/2 x^2 = 450

31.5

Step-by-step explanation:

64%

Step-by-step explanation:

[tex]\frac{45}{70}[/tex]x100 = 64.285714

hope this helped

Code in Python is given. Take note of the instruction in bold font

Explanation:

You will need to update the below two lines in your system based on the file path -

backward_phone_number('F:\\phone_number_input.txt','F:\\phone_number_output.txt')

def backward_phone_number(input_file,output_file):

ph_num_dictionary={}

entries=[]

with open(input_file,'r') as read_file:

entries=read_file.readlines()[1:]

for entry in entries:

ph_num_name=entry.split()

ph_number=ph_num_name[1].strip()

name=ph_num_name[0].strip()

if ph_num_dictionary.get(ph_number)==None:

name_list=[name]

ph_num_dictionary[ph_number]=name_list

else:

ph_num_dictionary.get(ph_number).append(name)

ph_num_dictionary = dict(sorted(ph_num_dictionary.items(),key=lambda pair:pair[0]))

with open(output_file,'w+') as write_file:

write_file.write('Telephone Number\tName\r\n')

for num,name in ph_num_dictionary.items():

if len(name)==1:

write_file.write(num+'\t'+name[0]+'\r\n')

else:

name.sort()

for person in name:

write_file.write(num + '\t' + person + '\r\n')

backward_phone_number('F:\\phone_number_input.txt','F:\\phone_number_output.txt')

given below.

Explanation:

1) a) the neutrally charged element in the nucleus of an atom --- Neutron

b) the number of protons an atom hasAtomic number

c) an atom of an element that has a different number of neutrons that the standard atom of that element isotopes

d) protons + neutrons in the nucleus of an atom Atomic mass

e) the positive particle in the nucleus of an atomProton

2) correct answer is option d)

because atomic number is less than atomic mass and atomic mass is nearly double to atomic mass so, best option leads to d.

3) correct answer is option d)

electron gives chemical properties to the atoms.

4) correct answer is option c)

proton is the element which give same number in all the atom.

5) neutral atom is one which have same number of electron and proton so, best option comes out to be b) which is Aluminium.

6) neutral atom of element has same number of electron and proton.

C is the correct answer

Number 17 mass 35.453

Question 1 is The neutrally charged element in the nucleus of an atom = neutron

the number of protons an atom has = atomic number

an atom that has a different number of neutrons than the standard = isotope

protons + neutrons = Atomic mass

positive particle = proton

Question 2 don't understand what you're asking

Question 3 = Protons. If you add or remove a proton, it becomes a different element.

Question 4 = same as 3 "Protons"

Question 5 again don't understand what you're asking

Question 6 = Protons and Electrons. A proton is positive and an electron is negative, so together it balances out

Question 7 is there like a chart or something to go with it? if not then I'll just define isotope. An Isotope is basically atoms of the same element (so the number of protons can't change) and has a different number of neutrons so since neutrons have a prominent mass(or weight(sort of)) relative to electrons then the mass number will be different as opposed to the standard mass number of an element. For example Chlorine(Cl) has 17 protons and 17 neutrons but there are variants of it like Cl-35 which has 17 protons and 18 neutrons.

Simply put an Isotope has a different number of neutrons than protons