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2 years ago

I need help on number 57.

Mathematics

1 answer:

Art [367]2 years ago

5 0

Multiply all prices by the number of the brand, and then multiply total number of brands by 80, den subtract

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Is 8−8−18 Commutative Property

prisoha [69]

Answer:

1. 8-8-18 =

0-18 =

-18

8 0

1 year ago

If y varies inversely as x and y=32 when x=3, find x when y=15

deff fn [24]

Y=kx, k is not equal to 0
when y=32,x=3, 32=3k
k=32/3
so y=32/3*x
when y=15, 15=32/3*x
x=45/32

5 0

3 years ago

<img src="https://tex.z-dn.net/?f=%20%5Cfrac%7B1%7D%7B%20%5Csqrt%7B2%7D%20%2B%201%20%7D%20%20%2B%20%20%5Cfrac%7B1%7D%7B%20%5Csqr

statuscvo [17]

Answer:

all i see is ..........

Step-by-step explanation:

8 0

2 years ago

6th grade math help me plzzz

Brut [27]

Answer:

a summary is an average and an average is mean

Step-by-step explanation:

to get the mean add all the cakes sold together then divide by number of years

21+28+19+26+21=115

115/5=23

so....

first one: mean

second one: 23

7 0

2 years ago

Read 2 more answers

Solve y'' + 10y' + 25y = 0, y(0) = -2, y'(0) = 11 y(t) = Preview

svetlana [45]

Answer: The required solution is

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

Step-by-step explanation: We are given to solve the following differential equation :

$y^{\prime\prime}+10y^\prime+25y=0,~~~~~~~y(0)=-2,~~y^\prime(0)=11~~~~~~~~~~~~~~~~~~~~~~~~(i)$

Let us consider that

$y=e^{mt}$ be an auxiliary solution of equation (i).

Then, we have

$y^prime=me^{mt},~~~~~y^{\prime\prime}=m^2e^{mt}.$

Substituting these values in equation (i), we get

$m^2e^{mt}+10me^{mt}+25e^{mt}=0\\\\\Rightarrow (m^2+10y+25)e^{mt}=0\\\\\Rightarrow m^2+10m+25=0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[\textup{since }e^{mt}\neq0]\\\\\Rightarrow m^2+2\times m\times5+5^2=0\\\\\Rightarrow (m+5)^2=0\\\\\Rightarrow m=-5,-5.$

So, the general solution of the given equation is

$y(t)=(A+Bt)e^{-5t}.$

Differentiating with respect to t, we get

$y^\prime(t)=-5e^{-5t}(A+Bt)+Be^{-5t}.$

According to the given conditions, we have

$y(0)=-2\\\\\Rightarrow A=-2$

and

$y^\prime(0)=11\\\\\Rightarrow -5(A+B\times0)+B=11\\\\\Rightarrow -5A+B=11\\\\\Rightarrow (-5)\times(-2)+B=11\\\\\Rightarrow 10+B=11\\\\\Rightarrow B=11-10\\\\\Rightarrow B=1.$

Thus, the required solution is

$y(t)=(-2+1\times t)e^{-5t}\\\\\Rightarrow y(t)=(-2+t)e^{-5t}.$

6 0

2 years ago