1 _ x 5 Please explain 4

If it takes 4 people 60 minutes to paint 8 walls, how long will it take 5 people to paint 4 walls?

m_a_m_a [10]

4 people paint 8 walls in 60 minutes

1 person paints 8 walls in 240 minutes

1 person paints 1 wall in 30 minutes

5 people paint 1 wall in 6 minutes

5 people paint 4 walls in 24 minutes

7 0

3 years ago

How many triangles exist with the given angle measures? 32°, 51°, 97°

irinina [24]

For each triangle sum of it's angles must add to 180°.
We need to check if these angles satisfy that condition:
32°+51°+97°=180°

They do satisfy. Now we check if any angle has value that is not possible.
32° and 51° angles are OK.
97° angle is also OK. It is obtuse angle.

For each angle measures exactly one triangle exists. In this example we have an obtuse-angle triangle.

6 0

3 years ago

I need help with Math please

Bess [88]

20 pages of stickers

6 0

3 years ago

Read 2 more answers

Mariah is incorrect because ?

Snowcat [4.5K]

She is incorect because
(a+b)^2 =a^2 +b^2+ 2ab

a + b
____###### If we sqare this will get:

____######
|.a^2|. ab |
|___ |######
# #. #
# ab #. b^2 #
#___ ######

7 0

3 years ago

Use the substitution x = et to transform the given Cauchy-Euler equation to a differential equation with constant coefficients.

Anika [276]

Answer:

$\boxed{\sf \ \ \ ax^2+bx^{-10} \ \ \ }$

Step-by-step explanation:

Hello,

let's follow the advise and proceed with the substitution

first estimate y'(x) and y''(x) in function of y'(t), y''(t) and t

$x(t)=e^t\\\dfrac{dx}{dt}=e^t\\y'(t)=\dfrac{dy}{dt}=\dfrac{dy}{dx}\dfrac{dx}{dt}=e^ty'(x)y'(x)=e^{-t}y'(t)\\y''(x)=\dfrac{d^2y}{dx^2}=\dfrac{d}{dx}(e^{-t}\dfrac{dy}{dt})=-e^{-t}\dfrac{dt}{dx}\dfrac{dy}{dt}+e^{-t}\dfrac{d}{dx}(\dfrac{dy}{dt})\\=-e^{-t}e^{-t}\dfrac{dy}{dt}+e^{-t}\dfrac{d^2y}{dt^2}\dfrac{dt}{dx}=-e^{-2t}\dfrac{dy}{dt}+e^{-t}\dfrac{d^2y}{dt^2}e^{-t}\\=e^{-2t}(\dfrac{d^2y}{dt^2}-\dfrac{dy}{dt})$

Now we can substitute in the equation

$x^2y''(x)+9xy'(x)-20y(x)=0\\ e^{2t}[ \ e^{-2t}(\dfrac{d^2y}{dt^2}-\dfrac{dy}{dt}) \ ] + 9e^t [ \ e^{-t}\dfrac{dy}{dt} \ ] -20y=0\\ \dfrac{d^2y}{dt^2}-\dfrac{dy}{dt}+ 9\dfrac{dy}{dt}-20y=0\\ \dfrac{d^2y}{dt^2}+ 8\dfrac{dy}{dt}-20y=0\\$