1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
wlad13 [49]
3 years ago
6

Doris made a list of all the whole number from 1 to 100 how many times did she write the digit 2

Mathematics
1 answer:
STALIN [3.7K]3 years ago
3 0
She wrote it 22 times
You might be interested in
Laticia randomly selected 25% of the seventh grade students in her school and asked them their favorite season. Of the students
Marysya12 [62]
I would say 75 or 150
 Do u know how many students are in her school?
4 0
2 years ago
Rationalize the denominator of sqrt -49 over (7 - 2i) - (4 + 9i)
zubka84 [21]
\sqrt{ \frac{-49}{(7-2i)-(4+9i) } } 


This one is quite the deal, but we can begin by distributing the negative on the denominator and getting rid of the parenthesis:

\frac{ \sqrt{-49}}{7-2i-4-9i}

See how the denominator now is more a simplification of like terms, with this I mean that you operate the numbers with an "i" together and the ones that do not have an "i" together as well. Namely, the 7 and the -4, the -2i with the -9i.
Therefore having the result: 

\frac{ \sqrt{-49} }{3-11i}

Now, the \sqrt{-49} must be respresented as an imaginary number, and using the multiplication of radicals, we can simplify it to \sqrt{49}  \sqrt{-1}
This means that we get the result 7i for the numerator.

\frac{7i}{3-11i}

In order to rationalize this fraction even further, we have to remember an identity from the previous algebra classes, namely: x^2 - y^2 =(x+y)(x-y)
The difference of squares allows us to remove the imaginary part of this fraction, leaving us with a real number, hopefully, on the denominator.

\frac{7i (3+11i)}{(3-11i)(3+11i)}

See, all I did there was multiply both numerator and denominator with (3+11i) so I could complete the difference of squares.
See how (3-11i)(3+11i)= 3^2 -(11i)^2 therefore, we can finally write:

\frac{7i(3+11i)}{3^2 - (11i)^2 }

I'll let you take it from here, all you have to do is simplify it further.
The simplification is quite straightforward, the numerator distributed the 7i. Namely the product 7i(3+11i) = 21i+77i^2.
You should know from your classes that i^2 = -1, thefore the numerator simplifies to -77+21i
You can do it as a curious thing, but simplifying yields the result:
\frac{-77+21i}{130}
7 0
3 years ago
Brainliest! Will give!Felicia had $80 when she went to a music store that charges $18 for each CD. She needs to have no less tha
Tju [1.3M]

3

dfihmuitwkgnuvjneoimndgfmh

3 0
3 years ago
Read 2 more answers
Mr. Nichols put $1,200 in a savings account at a local bank. The simple annual interest rate was 5%. How much interest did his a
satela [25.4K]

\bf ~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad  \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\to& \$1200\\ r=rate\to 5\%\to \frac{5}{100}\to &0.05\\ t=years\to &3 \end{cases} \\\\\\ I=(1200)(0.05)(3)\implies I=180

8 0
3 years ago
determine whether the triangles are similar if so what is the similarity statement and the postulate or theorem used.
zmey [24]
The triangles are similar because of the SAS postulate. The sides are proportional and angle T is equal in both.
6 0
3 years ago
Other questions:
  • How do i factor polynomials
    5·1 answer
  • (5Q) Which is the graph of the given function?
    5·1 answer
  • Which will hold more juice, 12cans which is 150 ml or 2 bottles which is 1 liter
    6·1 answer
  • A cell phone charger uses 5.6 Joules of energy per second when plugged
    13·1 answer
  • There are 140 members in a community sports program. Sixty-five percent of these members play soccer.
    15·1 answer
  • Could -2 be used as a base to rewrite 32? 64? why or why not ?
    5·1 answer
  • A dog and a cat are 200 meters apart when they see each other. The dog can run at a speed of 30 m/sec, while the cat can run at
    10·2 answers
  • Write the equation of a line parallel to the line y = 2x that passes through -2,-1
    9·2 answers
  • What is the error in the problem below
    12·1 answer
  • (
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!