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3 years ago

Math is to hard for meh

Mathematics

2 answers:

denis-greek [22]3 years ago

6 0

Answer:

C. 55

Step-by-step explanation:

20 * 2 3/4 = 20*2 + 20* 3/4 = 40 + 60/4 = 40 + 25 = 55

Another approach: you could rewrite 2 3/4 as 3 - 1/4

Then the question becomes:

20 * 3 - 20 * 1/4 = 60 - 20/4 = 60 - 5 = 55

sweet [91]3 years ago

3 0

Answer:

Step-by-step explanation:

2 and 3/4 is equal to 2.75 so just multiply 20 by 2.75 to get 55.

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A group of 15 friends take a trip to a water park. The total price of the trip is $599.85 before any discounts. The total price

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3 years ago

If x + y = 10 and x - y = 4, find the value of x² - y²

morpeh [17]

Answer:

x²-y² = 40

Step-by-step explanation:

Factorising x²-y²:

x²-y² = (x+y)(x-y)

This is due to the property that states:

a²+b² = (a+b)(a-b)

Substituting the given values into the above equation:

x²-y² = (10)(4)

= 40

Hence, x²-y² = 40

Hope this helps and be sure to have a wonderful time ahead at Brainly! :D

8 0

2 years ago

Read 2 more answers

Consider the differential equation:

Wewaii [24]

(a) Take the Laplace transform of both sides:

$2y''(t)+ty'(t)-2y(t)=14$

$\implies 2(s^2Y(s)-sy(0)-y'(0))-(Y(s)+sY'(s))-2Y(s)=\dfrac{14}s$

where the transform of $ty'(t)$ comes from

$L[ty'(t)]=-(L[y'(t)])'=-(sY(s)-y(0))'=-Y(s)-sY'(s)$

This yields the linear ODE,

$-sY'(s)+(2s^2-3)Y(s)=\dfrac{14}s$

Divides both sides by $-s$ :

$Y'(s)+\dfrac{3-2s^2}sY(s)=-\dfrac{14}{s^2}$

Find the integrating factor:

$\displaystyle\int\frac{3-2s^2}s\,\mathrm ds=3\ln|s|-s^2+C$

Multiply both sides of the ODE by $e^{3\ln|s|-s^2}=s^3e^{-s^2}$ :

$s^3e^{-s^2}Y'(s)+(3s^2-2s^4)e^{-s^2}Y(s)=-14se^{-s^2}$

The left side condenses into the derivative of a product:

$\left(s^3e^{-s^2}Y(s)\right)'=-14se^{-s^2}$

Integrate both sides and solve for $Y(s)$ :

$s^3e^{-s^2}Y(s)=7e^{-s^2}+C$

$Y(s)=\dfrac{7+Ce^{s^2}}{s^3}$

(b) Taking the inverse transform of both sides gives

$y(t)=\dfrac{7t^2}2+C\,L^{-1}\left[\dfrac{e^{s^2}}{s^3}\right]$

I don't know whether the remaining inverse transform can be resolved, but using the principle of superposition, we know that $\frac{7t^2}2$ is one solution to the original ODE.

$y(t)=\dfrac{7t^2}2\implies y'(t)=7t\implies y''(t)=7$

Substitute these into the ODE to see everything checks out:

$2\cdot7+t\cdot7t-2\cdot\dfrac{7t^2}2=14$

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3 years ago

How do you combine like terms and solve for the variable? 8 - 3x - 5x = -8

Nitella [24]

8 - 3x - 5x = -8
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2 years ago

Read 2 more answers