In a survey 230 people were asked their favorite color and 20% of the people surveyed choose blue. How many people choose blue?

A chemical company makes two brands of antifreeze. The first brand is 55 % pure antifreeze, and the second brand is 80 % pure an

Likurg_2 [28]

We have 55% and 80% antifreeze. We need 90 gallons of 75%.

F - 55% and E - 80%

A) F + E = 90

B) .55 F + .80 E = 67.50 (which is .75 * 90) Multiplying A) by -.55

A) -.55 F -.55 E = -49.50 (which is -.55 * 90) then adding A) & B)

.25 E = 18

E = 72 gallons of 80% and

F = 18 gallons of 55%

********* DOUBLE CHECK ******************

72 * .80 = 57.60 and 18 * .55 = 9.90

57.60 + 9.90 = 67.50 gallons of antifreeze and we have 90 total gallons

(67.50 / 90) * 100 = 75% correct!

Source: 1728.com/mixture.htm

3 0

3 years ago

Is 5.421 greater or less then 5.4

zavuch27 [327]

Greater than 5.4 i hate the 20 characters rule

5 0

3 years ago

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Use the method of undetermined coefficients to find the general solution to the de y′′−3y′ 2y=ex e2x e−x

djverab [1.8K]

I'll assume the ODE is

$y'' - 3y' + 2y = e^x + e^{2x} + e^{-x}$

Solve the homogeneous ODE,

$y'' - 3y' + 2y = 0$

The characteristic equation

$r^2 - 3r + 2 = (r - 1) (r - 2) = 0$

has roots at $r=1$ and $r=2$ . Then the characteristic solution is

$y = C_1 e^x + C_2 e^{2x}$

For nonhomogeneous ODE (1),

$y'' - 3y' + 2y = e^x$

consider the ansatz particular solution

$y = axe^x \implies y' = a(x+1) e^x \implies y'' = a(x+2) e^x$

Substituting this into (1) gives

$a(x+2) e^x - 3 a (x+1) e^x + 2ax e^x = e^x \implies a = -1$

For the nonhomogeneous ODE (2),

$y'' - 3y' + 2y = e^{2x}$

take the ansatz

$y = bxe^{2x} \implies y' = b(2x+1) e^{2x} \implies y'' = b(4x+4) e^{2x}$

Substitute (2) into the ODE to get

$b(4x+4) e^{2x} - 3b(2x+1)e^{2x} + 2bxe^{2x} = e^{2x} \implies b=1$

Lastly, for the nonhomogeneous ODE (3)

$y'' - 3y' + 2y = e^{-x}$

take the ansatz

$y = ce^{-x} \implies y' = -ce^{-x} \implies y'' = ce^{-x}$

and solve for $c$ .

$ce^{-x} + 3ce^{-x} + 2ce^{-x} = e^{-x} \implies c = \dfrac16$

Then the general solution to the ODE is

$\boxed{y = C_1 e^x + C_2 e^{2x} - xe^x + xe^{2x} + \dfrac16 e^{-x}}$

6 0

1 year ago

I need help quick!!<br><br> you can have brainliest this is algerbra btw

padilas [110]

Answer:

Step-by-step explanation:

Day 1 = 2 birds

day 2 = 3 birds

day 3 = 9 birds

day 4 = 8 birds

day 5 = 1 bird

On day 1 the points are (1,2)

On day 5 the points are (5,1)

(I am picking these for the points because I don't know your options for the selecting area.)

we use this formula y2-y1/x2-x1

2-5/1-1

3/0

our answer is infinite which is the relation and this is an infinite function

5 0

2 years ago

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you roll a six sided number cube and flip a coin what is the probability of rolling a number greater than 5 and flipping heads?

Whitepunk [10]

Answer:

0.08333... or 8.333...%

Step-by-step explanation:

1/6 * 1/2 = 1/12

5 0

2 years ago

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