When y=_7, find the value of 2y2- 9

Jack received $300 for his 13th birthday. If he saves it in a bank account with 8% interest compounded yearly, how much money wi

kari74 [83]

300(1.08)^5

440.798423

7 0

3 years ago

A cylinder has radius r and height h. A. How many times greater is the surface area of a cylinder when both dimensions are multi

Ierofanga [76]

Answer: A. Factor 2 => 4x greater

Factor 3 => 9x greater

Factor 5 => 25x greater

Step-by-step explanation: A. A cylinder is formed by 2 circles and a rectangle in the middle. That's why surface area is given by circumference of a circle, which is the length of the rectangle times height of the rectangle, i.e.:

A = 2.π.r.h

A cylinder of radius r and height h has area:

$A_{1}$ = 2πrh

If multiply both dimensions by a factor of 2:

$A_{2}$ = 2.π.2r.2h

$A_{2}$ = 8πrh

Comparing $A_{1}$ to $A_{2}$ :

$\frac{A_{2}}{A_{1}}$ = $\frac{8.\pi.rh}{2.\pi.rh}$ = 4

Doubling radius and height creates a surface area of a cylinder 4 times greater.

By factor 3:

$A_{3} = 2.\pi.3r.3h$

$A_{3} = 18.\pi.r.h$

Comparing areas:

$\frac{A_{3}}{A_{1}}$ = $\frac{18.\pi.r.h}{2.\pi.r.h}$ = 9

Multiplying by 3, gives an area 9 times bigger.

By factor 5:

$A_{5} = 2.\pi.5r.5h$

$A_{5} = 50.\pi.r.h$

Comparing:

$\frac{A_{5}}{A_{1}}$ = $\frac{50.\pi.r.h}{2.\pi.r.h}$ = 25

The new area is 25 times greater.

B. By analysing how many times greater and the factor that the dimensions are multiplied, you can notice the increase in area is factor². For example, when multiplied by a factor of 2, the new area is 4 times greater.

3 0

3 years ago

Can anyone help me with these questions i will mark you as brainliest

Aliun [14]

Answer:

X= 38

Step-by-step explanation:

A straight line is 180⁰ so we can subtract that by 133⁰ to get the degree on the inside of the triangle which is 47. You then add 47 and 95 to get 142. To get x you subtract 142 from 180

8 0

2 years ago

Their is a reservation fee of $47 and an additional hourly fee of $7.40 . The math club wants to spend less than $91.40 on renti

Margaret [11]

Answer: they can rent the room for less than 6 hours.

Step-by-step explanation:

Let x represent the possible amounts of time in which they can rent the room.

There is a reservation fee of $47 and an additional hourly fee of $7.40. This means that the total cost of renting the room for x hours would be

47 + 7.4x

The math club wants to spend less than $91.40 on renting the room. This would be expressed as

47 + 7.4x < 91.4

7.4x < 91.4 - 47

7.4x < 44.4

x < 44.4/7.4

x < 6

8 0

3 years ago

At jim's juice factory, his machine can fill 300 juice boxes an hour. Each box holds 0.8 cups How many gallons of juice does jim

anygoal [31]

300 boxes
0.8 cup per box

300 * 0.8 cups = 240 cups

There are 16 cups in a gallon.

240/16 gal = 15 gal

Answer: 15

5 0

3 years ago

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