Please help if you can:)

HELP ASAP!<br> Find the value of x. -1x + 72 = -3x + 84

hoa [83]

Answer:

x=6

Step-by-step explanation:

First, add x to each side.

72=-2x+84

Subtract 84 from each side

-12=-2x

Dive each side by -2

6=x

8 0

3 years ago

Read 2 more answers

Given: If a child is at least 4 feet tall, then

KIM [24]

Answer:

F

Step-by-step explanation:

7 0

3 years ago

) Use the Laplace transform to solve the following initial value problem: y′′−6y′+9y=0y(0)=4,y′(0)=2 Using Y for the Laplace tra

artcher [175]

Answer:

$y(t)=2e^{3t}(2-5t)$

Step-by-step explanation:

Let Y(s) be the Laplace transform Y=L{y(t)} of y(t)

Applying the Laplace transform to both sides of the differential equation and using the linearity of the transform, we get

L{y'' - 6y' + 9y} = L{0} = 0

(*) L{y''} - 6L{y'} + 9L{y} = 0 ; y(0)=4, y′(0)=2

Using the theorem of the Laplace transform for derivatives, we know that:

$\large\bf L\left\{y''\right\}=s^2Y(s)-sy(0)-y'(0)\\\\L\left\{y'\right\}=sY(s)-y(0)$

Replacing the initial values y(0)=4, y′(0)=2 we obtain

$\large\bf L\left\{y''\right\}=s^2Y(s)-4s-2\\\\L\left\{y'\right\}=sY(s)-4$

and our differential equation (*) gets transformed in the algebraic equation

$\large\bf s^2Y(s)-4s-2-6(sY(s)-4)+9Y(s)=0$

Solving for Y(s) we get

$\large\bf s^2Y(s)-4s-2-6(sY(s)-4)+9Y(s)=0\Rightarrow (s^2-6s+9)Y(s)-4s+22=0\Rightarrow\\\\\Rightarrow Y(s)=\frac{4s-22}{s^2-6s+9}$

Now, we brake down the rational expression of Y(s) into partial fractions

$\large\bf \frac{4s-22}{s^2-6s+9}=\frac{4s-22}{(s-3)^2}=\frac{A}{s-3}+\frac{B}{(s-3)^2}$

The numerator of the addition at the right must be equal to 4s-22, so

A(s - 3) + B = 4s - 22

As - 3A + B = 4s - 22

we deduct from here

A = 4 and -3A + B = -22, so

A = 4 and B = -22 + 12 = -10

It means that

$\large\bf \frac{4s-22}{s^2-6s+9}=\frac{4}{s-3}-\frac{10}{(s-3)^2}$

and

$\large\bf Y(s)=\frac{4}{s-3}-\frac{10}{(s-3)^2}$

By taking the inverse Laplace transform on both sides and using the linearity of the inverse:

$\large\bf y(t)=L^{-1}\left\{Y(s)\right\}=4L^{-1}\left\{\frac{1}{s-3}\right\}-10L^{-1}\left\{\frac{1}{(s-3)^2}\right\}$

we know that

$\large\bf L^{-1}\left\{\frac{1}{s-3}\right\}=e^{3t}$

and for the first translation property of the inverse Laplace transform

$\large\bf L^{-1}\left\{\frac{1}{(s-3)^2}\right\}=e^{3t}L^{-1}\left\{\frac{1}{s^2}\right\}=e^{3t}t=te^{3t}$

and the solution of our differential equation is

$\large\bf y(t)=L^{-1}\left\{Y(s)\right\}=4L^{-1}\left\{\frac{1}{s-3}\right\}-10L^{-1}\left\{\frac{1}{(s-3)^2}\right\}=\\\\4e^{3t}-10te^{3t}=2e^{3t}(2-5t)\\\\\boxed{y(t)=2e^{3t}(2-5t)}$

5 0

3 years ago

Plzz anwser ill give brainlest simplify 16- 8/15

Anton [14]

Answer:

232/15 [as an improper fraction] or 15 7/15 [as a mixed fraction]

Explanation:

16 - 8 / 15 =

(16) - (8 / 15) =

((16 × 15) / 15) - ((8) / 15) =

((240) / 15) - ((8) / 15) =

(240 - 8) / 15 =

232 / 15 =

15 7/15

7 0

2 years ago

1. Una escalera de 4 m de longitud se apoya sobre una pared vertical. Si la distancia entre la base de la escalera a la pared es

enot [183]

Answer:

puedes resolver de dos maneras si diste teorema de Pitágoras lo aplicas

hipotenusa al cuadrado = cateto 2 +cateto 2 ( el 2 significa al cuadrado)

sustituyes

hipotenusa= 4m

cateto= 2,5

hay que hallar el otro cateto que nos daría la altura a la que está la escalera

despejamos y tenemos

cateto 2= hip2 -cat2

cat2=(4)2-(2,5)2=

= 16-6,25=9,75

luego hallamos la raíz cuadrada de 9,75= 3,12

la altura a la que se encuentra es 3,12m

-si aun no diste Pitágoras podes representarlo en una hoja utilizando cm en lugar de metros( a escala). trazas el triángulo rectángulo la base te la da la distancia a la cual se encuentra la escalera de la pared es decir 2,5cm trazas la hipotenusa de 4cm de manera que coincida con el cateto opuesto , y mides el valor de este ,será de 3,12cm no olvides que la respuesta la debes dar en metros ya que es la unidad de medida que te da.

4 0

3 years ago