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3 years ago

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......................... HELP

1 answer:

mrs_skeptik [129]3 years ago

8 0

Answer:

b

Step-by-step explanation:

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Write a quadratic function, in standard form, that fits the set of points. Solve it as a system of three equations. (-4, 9), (0,

Tresset [83]

Answer:

$\boxed{y=2x^2+4x-7}$

Step-by-step explanation:

Let the quadratic function be

$y=ax^2+bx+c$

We substitute $(-4,9)$ into the equation to obtain;

$9=a(-4)^2+b(-4)+c$

$\Rightarrow 9=16a-4b+c---(1)$

We substitute $(0,-7)$ to obtain;

$-7=a(0)^2+b(0)^2+c$

$\Rightarrow c=-7---(2)$

We finally substitute $(1,-1)$ to obtain;

$-1=a(1)^2+b(1)^2+c$

$\Rightarrow -1=a+b+c---(3)$

We put equation (2) into equation (1) to get;

$9=16a-4b-7$

$16a-4b=16$

$\Rightarrow 4a-b=4---(4)$

$\Rightarrow -1=a+b-7$

$\Rightarrow a+b=6---(5)$

We add equation (4) and (5) to get;

$4a+a=6+4$

$\Rightarrow 5a=10$

$\Rightarrow a=2$

We put $a=2$ into equation (5) to get;

$2+b=6$

$\Rightarrow b=6-2$

$\Rightarrow b=4$

The reqiured quadratic function is

$y=2x^2+4x-7$

7 0

3 years ago

Inez waters her plants every two days. She trims them every 15 days. She did both today. When will she do them both again?

shtirl [24]

The answer is 30 days.

The solution for this is to find the least common multiple. By getting the multiple of both numbers.

Multiples of 2: 2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32,34,36,38,40…..

Multiples of 15: 15,30,45,60,75……..

The Least Common Multiples of 2 and 15 is 30. So, Inez will do them both again in 30 days.

The least common multiple (LCM) of two numbers is the smallest number that is multiple by the both number.

7 0

3 years ago

A fair coin is flipped twelve times. What is the probability of the coin landing tails up exactly nine times?

seraphim [82]

Answer:

$P\left(E\right)=\frac{55}{1024}$

Step-by-step explanation:

Given that a fair coin is flipped twelve times.

It means the number of possible sequences of heads and tails would be:

2¹² = 4096

We can determine the number of ways that such a sequence could contain exactly 9 tails is the number of ways of choosing 9 out of 12, using the formula

$nCr=\frac{n!}{r!\left(n-r\right)!}$

Plug in n = 12 and r = 9

$=\frac{12!}{9!\left(12-9\right)!}$

$=\frac{12!}{9!\cdot \:3!}$

$=\frac{12\cdot \:11\cdot \:10}{3!}$ ∵ $\frac{12!}{9!}=12\cdot \:11\cdot \:10$

$=\frac{1320}{6}$ ∵ $3!\:=\:3\times 2\times 1=6$

$=220$

Thus, the probability will be:

$P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}$

$=\frac{220}{4096}$

$=\frac{55}{1024}$

Thus, the probability of the coin landing tails up exactly nine times will be:

$P\left(E\right)=\frac{55}{1024}$

4 0

3 years ago

Please help i dont understand

Elena L [17]

Answer:

I think number one is 19

Step-by-step explanation:

8 0

3 years ago

In a nine-inning game, 12 of a baseball team’s 17 outs were fly balls. Fifty percent of the outs made by infielders and 100% of

Helga [31]

The right answer is 29 balls.

8 0

4 years ago