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2 years ago

I don't understand this problem can someone please help me

Mathematics

1 answer:

Stella [2.4K]2 years ago

5 0

ok kid you need to study instead of getting people to give you the answer

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What are the solutions of the equation (2x + 3)2 + 8(2x + 3) + 11 = 0

Tom [10]

Answer:

$x=\frac{-7-\sqrt{5}}{2}$ or $x=\frac{-7+ \sqrt{5}}{2}$

Step-by-step explanation:

The given equation is

$(2x+3)^2+8(2x+3)+11=0$

Let us treat this as a quadratic equation in $(2x+3)$ .

where $a=1,b=8,c=11$

The solution is given by the quadratic formula;

$(2x+3)=\frac{-b\pm \sqrt{b^2-4ac} }{2a}$

We substitute these values into the formula to obtain;

$(2x+3)=\frac{-8\pm \sqrt{8^2-4(1)(11)} }{2(1)}$

$(2x+3)=\frac{-8\pm \sqrt{64-44} }{2}$

$(2x+3)=\frac{-8\pm \sqrt{20} }{2}$

$(2x+3)=\frac{-8\pm2\sqrt{5} }{2}$

$(2x+3)=-4\pm \sqrt{5}$

$(2x+3)=-4-\sqrt{5}$ or $(2x+3)=-4+ \sqrt{5}$

$2x=-3-4-\sqrt{5}$ or $2x=-3-4+ \sqrt{5}$

$2x=-7-\sqrt{5}$ or $2x=-7+ \sqrt{5}$

$x=\frac{-7-\sqrt{5}}{2}$ or $x=\frac{-7+ \sqrt{5}}{2}$

5 0

3 years ago

Write the number below in expanded notation 75,966

aev [14]

7.596 to the 4th power

7 0

2 years ago

14a²b<br> 7a²b<br> =<br> Simplify

lidiya [134]

Step-by-step explanation:

if14a^2b/7a^2b answer is 2

and if the sign is addition then the answer is21a^2b if subtraction answer is7a^2b

4 0

2 years ago

Assume a plane is flying directly north at 200 mph, but there is a wind blowing west at 23 mph. Part I: Express both the velocit

yuradex [85]

Define i as a unit vector in the eastern direction.
Define j as a unit vector in the northern direction.

Part I
Because the wind is blowing west, its velocity vector is
-23i mph or as (-23, 0) mph
Because the plane is traveling north, its velocity vector is
200j mph or as (0, 200) mph

Part II
The actual velocity of the plane is the vector sum of the plane and wind velocities.
That is,
200j - 23i or (-23, 200) mph

Part III
The ground speed of the plane is the magnitude of its vector.
The ground speed is
√[200² + (-23)²] = 201.32 mph

The ground speed of the plane is 201.3 mph (nearest tenth)

Not:
The direction of the plane is
tan⁻¹ 23/200 = 6.56° west of north.

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3 years ago

You are considering developing a regression equation relating a dependent variable to two independent variables. One of the vari

lys-0071 [83]

Answer:

Step-by-step explanation:

a. How many dummy variables are needed to represent the categorical variable?

We need 1 less dummy variable than outcomes for the categorical variable.

categorical variable has 2 outcomes

So, we need 2-1 = 1 dummy variable.

Answer: 1

Note: If our categorical variable had 5 outcomes, we would need 5-1 = 4 dummy variables.

b. Write the multiple regression equation relating the dependent variable to the independent variables.

Note: Depending your your professor, this can be written one of the following ways...

yhat = a + b1 x1 + bx2

yhat = b0 + b1 x1 + b2 x2

yhat = beta0hat + beta1hat x1 + betahat2 x2

where x1 is the ratio variable

and x2 is the dummy variable

c. Interpret the meaning of the coefficients in the regression equation.

b0 = the predicted value of y when x1 and x2 both equal 0.

b1 = the change in y when x1 increases by 1 unit holding x2 constant.

b2 = the predicted difference in y between the two possible outcomes of the categorical variable holding x1 constant.

7 0

3 years ago