Andy is 2 years older than Jeff. In 5 years the sum of their ages will be 40.find their ages now

Which of the following is the method used to determine whether or not a proportion is true?

sdas [7]

Answer:

Cross multiplication is the method used to determine whether or not a proportion is true.

Explanation:

If you know one ratio in a proportion, you can use that information to find values in the other equivalent ratio.

Cross multiplication is the method used to determine whether or not a proportion is TRUE.

For example, if a bowl of fruit contains 10 oranges and 8 lemons, then the ratio of oranges to lemons is 10 is to 8 (that is, 10 : 8 ), which is equivalent to the ratio 5:4).

7 0

3 years ago

Which steps transform the graph of

vitfil [10]

Answer:

The correct option is the last one.

Step-by-step explanation:

To transform the graph of $y = x ^ 2$ into $y = -2(x - 2) ^ 2 + 2$ the following steps are fulfilled:

1) Move the graph 2 units to the right:

Let $y = f (x-2)$ then $y =(x-2) ^ 2$ Notice that the cut point has been moved to x = 2.

2) Reflect on the x axis:

To reflect a graph on the x-axis we do $y = -f(x)$ Then $f (x) = -(x-2) ^ 2$

3) Stretch according to factor 2.

For this we do $y = 2f(x)$

Then we have $f(x) = -2 (x-2) ^ 2$

4) Move up the graph in two units:

We do $y = f(x) +2$

Then $y = -2(x-2) ^ 2 +2.$

These steps coincide with those listed in the last option. Therefore the correct option is the last one.

"Translate 2 units on the right, reflect on the x-axis, stretch according to the factor 2 and translate 2 units"

4 0

3 years ago

Faron wants to paint the four walls in his bedroom. The room measures 12 ft long, 10 ft wide and 8 ft high. There are two doors

Rainbow [258]

Answer:

319 square feet.

Step-by-step explanation:

The walls of the room (the ones on the long side) have an area of 12 x 8 = 96 square feet each one. Thus, their area is 96 x 2= 192 square feet.

The other two walls have an area of 10 x 8 = 80 square feet each one. Thus, their area combined is 80 x 2 = 160 square feet.

Therefore, we have that the total area of the four walls is

192 +160 = 352 square feet

However, we have a door and a window that won't be painted.

The area of the door is: 3 x 7 =21 square feet

The area of the window is 3 x 4 = 12 square feet

Thus, the total amount of area that won't be painted is

21 + 12 = 33 square feet.

So we are going to take the total area minus the area that won't be painted to know the total area that Faron will pain:

352 - 33 = 319 square feet.

Thus, she will paint 319 square feet

4 0

3 years ago

Pls answer i'll mark u brainlist

In-s [12.5K]

Answer: 2/3 hours

Step-by-step explanation:

okay so the speed now is 850, which is 850/340 = 2.5 times the original speed

Since It's 2.5 times the original speed,

2.5x = 5/3

so x = 5/3/2.5 = 2/3

7 0

2 years ago

Read 2 more answers

Can someone help me with these questions and show work please and thank you

attashe74 [19]

Answer:

11. 78

12. 4x² - 3x - 1

Step-by-step explanation:

11. Sum of n whole numbers = ½(n² + n)

Multiply

½*n² + ½*n

= n²/2 + n/2

To find the sum of the first 12 whole number, substitute 12 for n into the equation.

= 12²/2 + 12/2

= 144/2 + 12/2

= 72 + 6

= 78

12. Area of trapezoid = ½(a + b)*h

Where,

a = 5x - 4

b = 3x + 2

h = x + 1

Area = ½(5x - 4 + 3x + 2)*(x + 1)

Area = ½(8x - 2)*(x + 1)

Area = ½[8x(x + 1) -2(x + 1)]

= ½[8x² + 8x - 2x - 2]

Add like terms

= ½(8x² - 6x - 2)

= ½(8x²) - ½(6x) - ½(2)

= 4x² - 3x - 1

6 0

2 years ago