Example 4
daniel's cell phone company offers a flat-rate unlimited texting plan for $25 per month. daniel's cost
per text in a given month depends on the number of texts he sent and received that month, according
to the function f(x) shown in the table. use the table to find and interpret the value of f-'(0.05).
25
50
100
150
200
300
400
500
750
1,000
1.00
0.50
0.25
0.17
0.13
0.08
0.06
0.05
0.03
0.03

step-by-step explanation:

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".

if you're trying to figure out how much each ounce cost it would be 0.20

cents each ounce