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3 years ago

Help pleaseeee xxxxxxxx

Mathematics

1 answer:

ASHA 777 [7]3 years ago

8 0

Answer:

is there multiple choices?

Step-by-step explanation:

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Martin is an artist who molds plaster into unique shapes.

Tanya [424]

Answer:

It is A. I took the test,

Step-by-step explanation:

its 66 and then the little 3

3 0

3 years ago

Richard and Teo have a combined age of 20. Richard is 2 years older than twice Teo’s age. How old are Richard and Teo?

boyakko [2]

Richard is 14 years old and Teo is 6 years old.

Step-by-step explanation:

Let,

Richard's age = x

Teo's age = y

Combined age = 20 years

According to given statement;

x+y=20 Eqn 1

x = 2y+2 Eqn 2

Putting value of x from Eqn 2 in Eqn 1

$(2y+2)+y=20\\2y+2+y=20\\3y=20-2\\3y=18$

Dividing both sides by 3

$\frac{3y}{3}=\frac{18}{3}\\y=6$

Putting y=6 in Eqn 2

$x=2(6)+2\\x=12+2\\x=14$

Richard is 14 years old and Teo is 6 years old.

Keywords: linear equation, substitution method

Learn more about substitution method at:

#LearnwithBrainly

5 0

3 years ago

Find a particular solution to the differential equation y′′+2y′+y=2t2−t+3e−2t. y′′+2y′+y=2t2−t+3e−2t.

Jlenok [28]

$y''+2y'+y=2t^2-t+3e^{-2t}$

The characteristic equation is

$r^2+2r+1=(r+1)^2=0\implies r=-1$

so the characteristic solution is

$y_c=C_1e^{-t}+C_2te^{-t}$

For the particular solution, we can try looking for a solution of the form

$y_p=at^2+bt+c+de^{-2t}$
$\implies{y_p}'=2at+b-2de^{-2t}$
$\implies{y_p}''=2a+4de^{-2t}$

Substituting into the ODE, we have

$(2a+4de^{-2t})+2(2at+b-2de^{-2t})+(at^2+bt+c+de^{-2t})=2t^2-t+3e^{-2t}$
$at^2+(4a+b)t+(2a+2b+c)+de^{-2t}=2t^2-t+3e^{-2t}$
$\implies\begin{cases}a=2\\4a+b=-1\\2a+2b+c=0\\d=3\end{cases}\implies a=2,b=-9,c=14,d=3$

So the general solution to the ODE is

$y=y_c+y_p$
$y=C_1e^{-t}+C_2te^{-t}+2t^2-9t+14+3e^{-2t}$