In 2017, there were about 21 million teenagers (aged 13-17) in the United States. They each
sent an average of 800 text messages per month. About how many text messages did all of the
teenagers in the United States send each month? Express your answer using scientific
notation. Show work for full credit.

The Number of text messages sent in a month is 1.68 ×

Step-by-step explanation:

Step 1 :

Total number of teenagers in United States = 21 million

Average text messages sent per month = 800

We need to find the number of text messages sent each month

Step 2 :

The number of text messages in a month can be computed by taking the product of the total number of teenagers and average messages sent per month

Therefore

Number of text messages that is sent in a month = 21 million ×  800

                                                                      = 21 × × 800

                                                                     = 168  × = 1.68 ×

Step 3 :

Answer :

The Number of text messages that is sent in a month is 1.68 ×

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation:

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.