Ask question

Ask question

All categories

3 years ago

14

Rafael can choose plan a or Plan B for his long-distance charges. For each plan, cost (in dollars) depends on minutes used (Per

month) as shown below.

1 answer:

PilotLPTM [1.2K]3 years ago

4 0

Answer:

a. Plan B; $4

b. 160 mins; Plan B

Step-by-step explanation:

a. Cost of Plan A for 80 minutes:

Find 80 on the x axis, and trave it up to to intercept the blue line (for Plan A). Check the y axis to see the value of y at this point. Thus:

f(80) = 8

This means Plan A will cost $8 for Rafael to 80 mins of long distance call per month.

Also, find the cost per month for 80 mins for Plan B. Use the same procedure as used in finding cost for plan A.

Plan B will cost $12.

Therefore, Plan B cost more.

Plan B cost $4 more than Plan A ($12 - $8 = $4)

b. Number of minutes that the two will cost the same is the number of minutes at the point where the two lines intercept = 160 minutes.

At 160 minutes, they both cost $16

The plan that will cost less if the time spent exceeds 160 minutes is Plan B.

You might be interested in

Anyone know what is 7(8+x+2)

Komok [63]

Answer: 7x + 70

Step-by-step explanation:

6 0

2 years ago

The system of equations may have a unique solution, an infinite number of solutions, or no solution. Use matrices to find the ge

Leno4ka [110]

Answer:

Infinite number of solutions.

Step-by-step explanation:

We are given system of equations

$5x+4y+5z=-1$

$x+y+2z=1$

$2x+y-z=-3$

Firs we find determinant of system of equations

Let a matrix A= $\left[\begin{array}{ccc}5&4&5\\1&1&2\\2&1&-1\end{array}\right]$ and B= $\left[\begin{array}{ccc}-1\\1\\-3\end{array}\right]$

$\mid A\mid=\begin{vmatrix}5&4&5\\1&1&2\\2&1&-1\end{vmatrix}$

$\mid A\mid=5(-1-2)-4(-1-4)+5(1-2)=-15+20-5=0$

Determinant of given system of equation is zero therefore, the general solution of system of equation is many solution or no solution.

We are finding rank of matrix

Apply $R_1\rightarrow R_1-4R_2$ and $R_3\rightarrow R_3-2R_2$

$\left[\begin{array}{ccc}1&0&1\\1&1&2\\0&-1&-3\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\1\\-5\end{array}\right]$

Apply $R_2\rightarrow R_2-R_1$

$\left[\begin{array}{ccc}1&0&1\\0&1&1\\0&-1&-3\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\6\\-5\end{array}\right]$

Apply $R_3\rightarrow R_3+R_2$

$\left[\begin{array}{ccc}1&0&1\\0&1&1\\0&0&-2\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\6\\1\end{array}\right]$

Apply $R_3\rightarrow- \frac{1}{2}$ and $R_2\rightarrow R_2-R_3$

$\left[\begin{array}{ccc}1&0&1\\0&1&0\\0&0&1\end{array}\right]$ : $\left[\begin{array}{ccc}-5\\\frac{13}{2}\\-\frac{1}{2}\end{array}\right]$

Apply $R_1\rightarrow R_1-R_3$

$\left[\begin{array}{ccc}1&0&0\\0&1&0\\0&0&1\end{array}\right]$ : $\left[\begin{array}{ccc}-\frac{9}{2}\\\frac{13}{2}\\-\frac{1}{2}\end{array}\right]$

Rank of matrix A and B are equal.Therefore, matrix A has infinite number of solutions.

Therefore, rank of matrix is equal to rank of B.

4 0

3 years ago

A drilling crew dug to a depth of 26 ½ feet during their first day of drilling. On the second day, the crew dug down 9½ feet mor

Neporo4naja [7]

The depth of the bottom of the hole after the second day is 36 feet using addition operation.

<h3>What is addition?</h3>

In math, addition is the process of adding two or more integers together. Addends are the numbers that are added, while the sum refers to the outcome of the operation.

Given the depth on the first day is 26 ½ feet.

Depth on the second day = 9½ feet more than on the first day i.e. 9½ feet + depth on the first day

This implies, depth on the second day = 9½ + 26 ½

= 36 feet

Therefore, the depth of the bottom of the hole after the second day is 36 feet.

To learn more about addition, visit:

brainly.com/question/25621604

#SPJ9

5 0

1 year ago

State the domain of the relation {(4, 5), (2, 3), (−3, 0), (2, 1)}.

adelina 88 [10]

Answer:

4,2,-3,2

Step-by-step explanation:

Domain is all the X values

7 0

3 years ago

Chelsea played her tuba from 4:25 pm until 5:07

melisa1 [442]

Answer:

42 minutes

Step-by-step explanation:

if you are asking how long it takes Chelsea to play her tuba then you do: 67 - 25 = 42

7 0

3 years ago