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ElenaW [278]
3 years ago
9

Dave is three times as old as his sister. In seven years the sum of their ages will be 38. How old are they now?

Mathematics
1 answer:
bija089 [108]3 years ago
7 0

Answer:

Dave is 18 and his sister is 6.

Step-by-step explanation:

If you do 38 -7x2 you can work out the combined ages of them now which is 24 (you have to do 7x2 because there are two of them and its seven years in the future). Then you can work out their ages using a ratio. Dave’s age : his sister’s age is 3:1 so if you divide 24 by 4 (3+1 = 4 so your can work out one portion of their age) you can find out how old the sister is which is 6. Times that by 3 to get Dave’s age which is 18. A formula for this (where x is his sisters age) would be 3x=38-7x2 which cancels down to 6.

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On a piece of paper graph y < 2x - 3 then determine
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Answer

3.5

Step-by-step explanation:

y < 2x - 3 = 3.5

2x is greater than y and y is an unknown value you can solve this by using a two step equation

5 0
3 years ago
Let’s look at another one of Homer’s rocket launches. It was launched from ground level with an initial velocity of 208 feet per
kozerog [31]

Answer:

Smax = 676 ft

the maximum altitude (height) the rocket will attain during its flight is 676 ft

Step-by-step explanation:

Given;

The height function S(t) of the rocket as;

S(t) = -16t2 + 208t

The maximum altitude Smax, will occur at dS/dt = 0

differentiating S(t);

dS/dt = -32t + 208 = 0

-32t +208 = 0

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t = 208/32

t = 6.5 seconds.

The maximum altitude Smax is;

Substituting t = 6.5 s

Smax = -16(6.5)^2 + 208(6.5)

Smax = 676 ft

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8 0
3 years ago
Can you please tell me the table of 12?
zloy xaker [14]

Answer:

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Step-by-step explanation:

7 0
3 years ago
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Which measure of variation is found by placing the data in ascending order and subtracting the lowest value from the highest val
igomit [66]

Answer:

Range

Step-by-step explanation:

The range of a given set of data is the difference between the largest value and the smallest value in the data. For convenience and ease in the calculation, it is advisable to place the data in ascending order.

For example, given the following set of data:

4,9,5,6,2

To find the range;

<em>=> First arrange the data in ascending order</em>

2,4,5,6,9

<em>=> Find the smallest and largest numbers and then find their difference.</em>

Since the data has been arranged, it is obvious to see that the smallest number is <em>2</em> and the largest number is <em>9.</em>

Therefore the;

range = 9 -2 = 7

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vovikov84 [41]
I haven’t met them but they seem like very nice fun people ...
Have you met them? :)
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