In a certain country, a letter up to 1 ounce requires postage in the amount of $0.42, and each additional ounce (or fraction of an ounce) has an additional cost. the function below represents the cost of mailing one letter in this country. f(c)=0.42 + 0.20[x-1] josiah has two letters. the first weighs 2.9 ounces, and the second weighs 4.1 ounces. what is the total amount josiah can expect to pay for postage? $1.62 $1.64 $1.84 $2.04

Total amount Josiah can expect to pay for postage is:

$ 1.84

Step-by-step explanation:

cost of mailing one letter in the country is:

f(x)=0.42 + 0.20[x-1]

The first weighs 2.9 ounces, and the second weighs 4.1 ounces.

Cost of mailing first letter=0.42+0.20(2.9-1)

                                         =0.42+0.38

                                         =$ 0.8

Cost of mailing second letter=0.42+0.20(4.1-1)

                                               =0.42+0.62

                                               =$ 1.04

total cost=$(0.8+1.04)

              =$ 1.84

Hence, total amount Josiah can expect to pay for postage is:

$ 1.84

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional