Two questions, answer correctly.

To the nearest millimeter, a cell phone is 105 mm long and 66 mm wide. What is the ratio of the width to the length?

makvit [3.9K]

Answer:

22:35

Step-by-step explanation:

Find the GCD (or HCF) of numerator and denominator

GCD of 66 and 105 is 3

Divide both the numerator and denominator by the GCD

66 ÷ 3/105 ÷ 3

Reduced fraction:

22/35

therefore the ratio will be 22:35

3 0

3 years ago

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

Kitty Foods sells their cat food in 3 3/4 lb bags, while Cat Caterers sells 2 1/8 lb bags. How much bigger are the bags Kitty Fo

Mariulka [41]

Answer: The answer for the question is: 1 5/8

Step-by-step explanation:

8 0

1 year ago

Find the product.

4vir4ik [10]

Answer :

$6{y}^{4} {z}^{2} + 12 {y}^{3} {z}^{2}-3 {y}^{3} {z}+3 {y}^{2} {z}^{2}$

Step-by-step explanation :

To find the product of

$3 {y}^{2} z(2 {y}^{2} z + 4yz - y + z)$

First we expand the bracket ,

it implies that, we use the expression outside the bracket to multiply individual expressions inside the bracket.

Hence

$3 {y}^{2} z(2 {y}^{2} z + 4yz - y + z)$

$= 3 {y}^{2} z(2 {y}^{2} z) + 3 {y}^{2} z(4yz) - 3 {y}^{2} z(y )+3 {y}^{2} z( z)$

we now apply the law of indices

${a}^{m} \times {a}^{n} = {a}^{m+n}$

meaning, when you are multiplying two expressions with the same bases , repeat one of the bases and add the exponents.

Then, simplify to obtain

$= 6{y}^{4} {z}^{2} + 12 {y}^{3} {z}^{2}-3{y}^{3} {z}+3 {y}^{2} {z}^{2}$

3 0

2 years ago

An acute angle θ is in a right triangle with sin θ = five sixths. What is the value of cot θ?

Molodets [167]

<span>The value of cot is √13/6</span>

6 0

3 years ago