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4 years ago

3x + 7 - x + 2 A.2x + 9 B.2x + 5 C.4x + 9 D.4x - 5

Mathematics

2 answers:

xz_007 [3.2K]4 years ago

4 0

Answer:

Step-by-step explanation:

3x + 7 - x + 2 combine like terms

3x - x + 7 + 2

2x + 9

Option A

Jobisdone [24]4 years ago

3 0

The answer is letter A

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Follow the process of completing the square to solve 2x2 + 8x - 12 = 0. After adding B2 to both sides of the equation in step 4,

valentina_108 [34]

2x2 + 8x - 12 = 0
4 + 8x - 12 = 0
8x = 12 - 4
8x = 8
x = 1

4 0

3 years ago

HELP ME I WILL GIVE YOU BRAINLIEST AND A 5.0 REVIEW

Jlenok [28]

Answer:

Base

Step-by-step explanation:

A power is the product of multiplying a number by itself. Usually, a power is represented with a base number and an exponent. The base number tells what number is being multiplied. The exponent, a small number written above and to the right of the base number, tells how many times the base number is being multiplied.

4 0

3 years ago

Marine biologists have determined that when a shark detectsthe presence of blood in the water, it will swim in the directionin w

siniylev [52]

Solution :

a). The level curves of the function :

$C(x,y) = e^{-(x^2+2y^2)/10^4}$

are actually the curves

$e^{-(x^2+2y^2)/10^4}=k$

where k is a positive constant.

The equation is equivalent to

$x^2+2y^2=K$

$\Rightarrow \frac{x^2}{(\sqrt K)^2}+\frac{y^2}{(\sqrt {K/2})^2}=1, \text{ where}\ K = -10^4 \ln k$

which is a family of ellipses.

We sketch the level curves for K =1,2,3 and 4.

If the shark always swim in the direction of maximum increase of blood concentration, its direction at any point would coincide with the gradient vector.

Then we know the shark's path is perpendicular to the level curves it intersects.

b). We have :

$\triangledown C= \frac{\partial C}{\partial x}i+\frac{\partial C}{\partial y}j$

$\Rightarrow \triangledown C =-\frac{2}{10^4}e^{-(x^2+2y^2)/10^4}(xi+2yj),$ and

$\triangledown C$ points in the direction of most rapid increase in concentration, which means $\triangledown C$ is tangent to the most rapid increase curve.

$r(t)=x(t)i+y(t)j$ is a parametrization of the most $\text{rapid increase curve}$ , then

$\frac{dx}{dt}=\frac{dx}{dt}i+\frac{dy}{dt}j$ is a tangent to the curve.

So then we have that $\frac{dr}{dt}=\lambda \triangledown C$

$\Rightarrow \frac{dx}{dt}=-\frac{2\lambda x}{10^4}e^{-(x^2+2y^2)/10^4}, \frac{dy}{dt}=-\frac{4\lambda y}{10^4}e^{-(x^2+2y^2)/10^4}$

∴ $\frac{dy}{dx}=\frac{dy/dt}{dx/dt}=\frac{2y}{x}$

Using separation of variables,

$\frac{dy}{y}=2\frac{dx}{x}$

$\int\frac{dy}{y}=2\int \frac{dx}{x}$

$\ln y=2 \ln x$

⇒ y = kx^2 for some constant k

but we know that $y(x_0)=y_0$

$\Rightarrow kx_0^2=y_0$

$\Rightarrow k =\frac{y_0}{x_0^2}$

∴ The path of the shark will follow is along the parabola

$y=\frac{y_0}{x_0^2}x^2$

$y=y_0\left(\frac{x}{x_0}\right)^2$

7 0

3 years ago

40x=10x^2+41 <br><br> Identify the number of solutions and their types using the discriminant

nydimaria [60]

Number of solutions: no roots

Type of solution: Not Real

Step-by-step explanation:

We need to identify the number of solutions and their types using the discriminant.

We are given: $40x=10x^2+41\\$

Rearranging:

$40x-10x^2-41=0\\10x^2-40x+41=0$

Discriminant can be found by: $b^2-4ac$

where b=-40, a=10 and c=41

Putting values:

$b^2-4ac\\=(-40)^2-4(10)(41)\\=1600-1640\\=-40\\$

So, Discriminant is -40

If the discriminant is less than zero i.e -40 then there are no real roots.

So, Number of solutions: no roots

Type of solution: Not Real

Keywords: discriminant

Learn more about discriminant at:

#learnwithBrainly

6 0

3 years ago

In 1997 there were 31 laptop computers at Grove High School. Starting in 1998 the school bought 20 more laptop computers at the

Kruka [31]

Using the linear equation, T = 20x + 31, the total number of computers at the end of 2005 is: C. 191.

<h3>How to Use a Linear Equation?</h3>

A linear equation is expressed as y = mx + b, where x is a function of y, m is the rate of change and b is the y-intercept or starting value.

In the scenario stated, we are given the linear equation for total number of laptop computers at the school after 1997 as, T = 20x + 31.

Rate of change = 20

y-intercept/starting value = 31

x = 2005 - 1997 = 8

To find the total number of laptop computers at Grove High School at the end of 2005 (T), substitute x = 8 into the equation, T = 20x + 31.

T = 20(8) + 31

T = 160 + 31

T = 191 computers.

Thus, total number of computers at the end of 2005 is: C. 191.

Learn more about linear equation on:

brainly.com/question/15602982

#SPJ1

7 0

2 years ago