All categories

2 years ago

Alex stayed up 20 a week How many hours did Alex stay up in 12 weeks?

Mathematics

1 answer:

Simora [160]2 years ago

3 0

Answer:

240 hours

Step-by-step explanation:

1 week = 20 hours

12 weeks = 20 × 12

= 240 hours

You might be interested in

I need help with the answer

solmaris [256]

Answer:

Its the last option

y = 1488.33x + 23800 ; $172,600.

Step-by-step explanation:

The slope of the trend line = (median value for 2000 - median value for 1940) / 60

= 89300 / 60

= 1488.33.

So the equation is 1488.33x + 23,800

Estimate for 2040

is 1483.33* 100 + 23800

= 172,600.

5 0

3 years ago

Which number belongs to the solution set of the equation below?

ollegr [7]

The correct answer would be: C. 44
Explanation: If you're trying to find out x's value, you have to do the inverse operation which means if it's subtraction, you add. So to find x's value, you'd add 36 + 8 = x. And 36 + 8 = 44. So therefore, x = 44. That means the answer is C.

5 0

3 years ago

(10 points) Consider the initial value problem y′+3y=9t,y(0)=7. Take the Laplace transform of both sides of the given differenti

Rashid [163]

Answer:

The solution

$Y (s) = 9( -1 +3 t + e^{-3 t} ) + 7 e ^{-3 t}$

Step-by-step explanation:

Explanation:-

Consider the initial value problem y′+3 y=9 t,y(0)=7

Step(i):-

Given differential problem

y′+3 y=9 t

Take the Laplace transform of both sides of the differential equation

L( y′+3 y) = L(9 t)

Using Formula Transform of derivatives

L(y¹(t)) = s y⁻(s)-y(0)

By using Laplace transform formula

$L(t) = \frac{1}{S^{2} }$

Step(ii):-

Given

L( y′(t)) + 3 L (y(t)) = 9 L( t)

$s y^{-} (s) - y(0) + 3y^{-}(s) = \frac{9}{s^{2} }$

$s y^{-} (s) - 7 + 3y^{-}(s) = \frac{9}{s^{2} }$

Taking common y⁻(s) and simplification, we get

$( s + 3)y^{-}(s) = \frac{9}{s^{2} }+7$

$y^{-}(s) = \frac{9}{s^{2} (s+3}+\frac{7}{s+3}$

Step(iii):-

By using partial fractions , we get

$\frac{9}{s^{2} (s+3} = \frac{A}{s} + \frac{B}{s^{2} } + \frac{C}{s+3}$

$\frac{9}{s^{2} (s+3} = \frac{As(s+3)+B(s+3)+Cs^{2} }{s^{2} (s+3)}$

On simplification we get

9 = A s(s+3) +B(s+3) +C(s²) ...(i)

Put s =0 in equation(i)

9 = B(0+3)

B = 9/3 = 3

Put s = -3 in equation(i)

9 = C(-3)²

C = 1

Given Equation 9 = A s(s+3) +B(s+3) +C(s²) ...(i)

Comparing 'S²' coefficient on both sides, we get

9 = A s²+3 A s +B(s)+3 B +C(s²)

0 = A + C

put C=1 , becomes A = -1

$\frac{9}{s^{2} (s+3} = \frac{-1}{s} + \frac{3}{s^{2} } + \frac{1}{s+3}$

Step(iv):-

$y^{-}(s) = \frac{9}{s^{2} (s+3}+\frac{7}{s+3}$

$y^{-}(s) =9( \frac{-1}{s} + \frac{3}{s^{2} } + \frac{1}{s+3}) + \frac{7}{s+3}$

Applying inverse Laplace transform on both sides

$L^{-1} (y^{-}(s) ) =L^{-1} (9( \frac{-1}{s}) + L^{-1} (\frac{3}{s^{2} }) + L^{-1} (\frac{1}{s+3}) )+ L^{-1} (\frac{7}{s+3})$

By using inverse Laplace transform

$L^{-1} (\frac{1}{s} ) =1$

$L^{-1} (\frac{1}{s^{2} } ) = \frac{t}{1!}$

$L^{-1} (\frac{1}{s+a} ) =e^{-at}$

Final answer:-

Now the solution , we get

$Y (s) = 9( -1 +3 t + e^{-3 t} ) + 7 e ^{-3t}$

5 0

3 years ago

if the area of a rectangle is expressed as x^4 - 9y^2, then the product of the length and the width of the rectangle could be ex

kvasek [131]

Answer:the product of the length and the width of the rectangle could be expressed as

(x^2 - 3y)(x^2 + 3y)

Step-by-step explanation:

If the area of a rectangle is expressed as x^4 - 9y^2, we would determine the dimensions by simplifying the given expression. The simplified expression becomes

(x^2 - 3y)(x^2 + 3y)

Let us check by multiplying each term in one parenthesis by each term in the other parenthesis to get the given expression. It becomes

(x^2 - 3y)(x^2 + 3y) = x^4 + 3x^2y - 3x^2y - 9y^2 = x^4 - 9y^2

6 0

3 years ago

PLS HELP!!!!!!!!!!!!!!!! I got all the way to 4 x <img src="https://tex.z-dn.net/?f=%5Csqrt%7B6250" id="TexFormula1" title="

crimeas [40]

Answer:

No its not right :(

The correct answer should be 100 root 10, or around 316.23

3 0

1 year ago