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3 years ago

Write down a 3-digit number where digits are in decreasing order. Reverse the digits and subtract it from the first number.

Mathematics

1 answer:

Alla [95]3 years ago

8 0

Step-by-step explanation:

987 → 789

987 - 789 = 198

876 → 678

876 - 678 = 198

765 → 567

765 - 567 = 198

654 → 456

654 - 456 = 198

543 → 345

543 - 345 = 198

432 → 234

432 - 234 = 198

321 → 123

321 - 123 = 198

Generally it is always like that:

3 ≤ x ≤ 9

100x + 10(x-1) + (x - 2) → 100(x - 2) + 10(x - 1) + x

(100x + 10(x - 1) + (x - 2)) - (100(x-2) + 10(x-1) + x)

= 100x + 10(x - 1) + (x - 2) - 100(x - 2) - 10(x - 1) - x cancel 10(x - 1)

= 100x + x - 2 - 100x + 200 - x cancel 100x and x

= 100 - 2

= 198

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a volley ball player servers the ball. The ball follows a path given by the equation y=-0.01x^2+0.5x+3 where x and y are measure

dolphi86 [110]

Answer:

(a)

Distance from player should be 13.82 feet or 36.2 feet

(b)

The ball will go over the net

Step-by-step explanation:

we are given

The ball follows a path given by the equation

$y=-0.01x^2+0.5x+3$

where

x and y are measured in feet and the origin is on the court directly below where the player hits the ball

(a)

net height is 8 ft

so, we can set y=8

and then we can solve for x

$8=-0.01x^2+0.5x+3$

$8\cdot \:100=-0.01x^2\cdot \:100+0.5x\cdot \:100+3\cdot \:100$

$800=-x^2+50x+300$

$-x^2+50x-500=0$

$x^2-50x+500=0$

we can use quadratic formula

$x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$x=\frac{-50\pm \sqrt{50^2-4\left(-1\right)\left(-500\right)}}{2\left(-1\right)}$

$x=5\left(5-\sqrt{5}\right),\:x=5\left(5+\sqrt{5}\right)$

$x=13.82,x=36.2$

So, distance from player should be 13.82 feet or 36.2 feet

(b)

we can plug x=30 and check whether y=8 ft

$y=-0.01(30)^2+0.5(30)+3$

$y=9ft$

we know that

height of net is 8 ft

so, the ball will go over the net

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3 years ago

Q and R are independent events. if P(Q)= 1/4 and P (R)= 1/5, find P(Q and R)

Setler79 [48]

Answer:

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3 years ago

What additional doubles fact can help you find 4+3? Explain how you know

Anna35 [415]

Answer:

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Step-by-step explanation:

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2 years ago

Which of the following correctly uses the additive inverse property

Vladimir [108]

What are the choices can’t help if there’s so choices to choose from

7 0

2 years ago

Read 2 more answers

Suppose g (x) is increasing and concave up everywhere and g(A)=7, gprime(A)=13, h=.01

rewona [7]

First we need a point (x,y) : (A, 7)
Now slope (from f'(A)) = 15 
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y - 7 = 15 (x -A) 
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8 0

3 years ago