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2 years ago

Complete the recursive formula of the arithmetic sequence 20, 26, 32, 38, ....

Mathematics

1 answer:

svp [43]2 years ago

6 0

Step-by-step explanation:

a(n) = a +(n-1)d

a=20

d=26-20=6

°.° a(n) = 20 +(n–1)6

a(1) = 20 +(1–1)6=20

hope this helps

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On the last day of school, Mrs. Awesome gave jelly beans to her class. She gave each boy as many jelly beans as there were boys

professor190 [17]

Answer:

28 students

Step-by-step explanation:

Let x be the number of girls in the class. There were two more boys than girls in her class, then the number of boys is x + 2.

Mrs. Awesome gave each boy as many jelly beans as there were boys in the class, so each of x + 2 boys got x + 2 jelly beans, so

Number of boys = x + 2

Number of jelly beans each boy got = x + 2

Total number of jelly beans all boys got = (x + 2)(x + 2)

Mrs. Awesome gave each girl as many jelly beans as there were girls in the class, so each of x girls got x jelly beans, so

Number of girls = x

Number of jelly beans each girl got = x

Total number of jelly beans all girls got = (x)(x)

Hence,

Total number of jelly beans class got = (x + 2)(x + 2) + (x)(x)

Mrs. Awesome brought 400 jelly beans, and when she finished, she had six jelly beans left, so she gave 400 - 6 = 394 jelly beans to the calss.

So,

$(x+2)(x+2)+(x)(x)=394\\ \\x^2+2x+2x+4+x^2=394\\ \\2x^2+4x+4-394=0\\ \\2x^2+4x-390=0\\ \\x^2+2x-195=0\\ \\D=2^2-4\cdot (-195)=4+780=784\\ \\\sqrt{D}=28\\ \\x_{1,2}=\dfrac{-2\pm 28}{2\cdot 1}=-15,\ 13$

Number of girls cannot be negative, so x = 13, x + 2 = 15 and total number of students is 13 + 15 = 28

3 0

3 years ago

An ice cream store has the pricing shown below. You want to determine the best value. The height of the cone is 4.5 in and the d

nignag [31]

Solution:

Step 1:

We will calculate the volume of ice cream in the single scoop

The volume of the ice cream will be

$\begin{gathered} V=\frac{1}{3}\pi r^2h+\frac{2}{3}\pi r^3 \\ r=\frac{2in}{2}=1in(cone) \\ h=4.5in \\ r=\frac{3in}{2}=1.5in(radius\text{ of the hemisphere\rparen} \end{gathered}$

By substituting the values, we will have

$\begin{gathered} V=\frac{1}{3}\pi r^{2}h+\frac{2}{3}\pi r^{3} \\ V=\frac{1}{3}\times\frac{22}{7}\times1^2\times4.5+\frac{2}{3}\times\frac{22}{7}\times1.5^3 \\ V=\frac{33}{7}+\frac{99}{14} \\ V=\frac{165}{14} \\ V=11.79in^3 \end{gathered}$

Step 2:

We will use the formula below to calculate the volume of the two scoops of ic cream

$\begin{gathered} V=\frac{1}{3}\pi r^2h+\frac{4}{3}\pi r^3 \\ V=\frac{1}{3}\times\frac{22}{7}\times1^2\times4.5in+\frac{4}{3}\times\frac{22}{7}\times1.5^3 \\ V=\frac{33}{7}+\frac{99}{7} \\ V=\frac{132}{7} \\ V=18.86in^3 \end{gathered}$

Step 3:

We will use the formula below to calculate the volume of the three scoops of ic cream

$\begin{gathered} V=\frac{1}{3}\pi r^2h+\frac{6}{3}\pi r^3 \\ V=\frac{1}{3}\times\frac{22}{7}\times1^2\times4.5+2\times\frac{22}{7}\times1.5^3 \\ V=\frac{33}{7}+\frac{297}{14} \\ V=\frac{363}{14} \\ V=25.93in^3 \end{gathered}$

For the first ice cream with one scoop