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3 years ago

If the dimensions of a rectangle are a+3b and a−3b, what is the area of the rectangle in terms of a and b?

Mathematics

1 answer:

ss7ja [257]3 years ago

8 0

Area=legnth times width
we notice this is a special case
(a+b)(a-b)=a^2-b^2

area=(a+3b)(a-3b)=a^2-9b^2

area=a^2-9b^2

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Find P(Q|R) A. 3/22 B. 3/7 C. 8/15 D. 8/11

joja [24]

Answer: the answer is C

Step-by-step explanation:

4 0

3 years ago

What is the probability of rolling a three on the first die and a two on the second die?

Neporo4naja [7]

The two rolls of the number cube are independent events because
the result of 1 roll does not affect the result of the other roll.
To find the probability of two independent events, we first find
the probability of each event, then we multiply the probabilities.
We can find the probability of an event using the following ratio:
number of favorable outcomes/total number of outcomes
Since there is only one way to roll a 3 and there are six
possible outcomes, 1, 2, 3, 4, 5, and 6, the probability of rolling a 3 is 1/6.
Since there is also only one way to roll a 2 and there are
six possible outcomes, the probability of rolling a 2 would be 1/6.
Now we multiply the probabilities.
1/6 x 1/6 is 1/36.
So the probability of rolling a 3 and a 2 is 1/36.

8 0

3 years ago

Read 2 more answers

Let c be a positive number. A differential equation of the form dy/dt=ky^1+c where k is a positive constant, is called a doomsda

stich3 [128]

Answer:

The doomsday is 146 days

Step-by-step explanation:

Given

$\frac{dy}{dt} = ky^{1 +c}$

First, we calculate the solution that satisfies the initial solution

Multiply both sides by

$\frac{dt}{y^{1+c}}$

$\frac{dt}{y^{1+c}} * \frac{dy}{dt} = ky^{1 +c} * \frac{dt}{y^{1+c}}$

$\frac{dy}{y^{1+c}} = k\ dt$

Take integral of both sides

$\int \frac{dy}{y^{1+c}} = \int k\ dt$

$\int y^{-1-c}\ dy = \int k\ dt$

$\int y^{-1-c}\ dy = k\int\ dt$

Integrate

$\frac{y^{-1-c+1}}{-1-c+1} = kt+C$

$-\frac{y^{-c}}{c} = kt+C$

To find c; let t= 0

$-\frac{y_0^{-c}}{c} = k*0+C$

$-\frac{y_0^{-c}}{c} = C$

$C =-\frac{y_0^{-c}}{c}$

Substitute $C =-\frac{y_0^{-c}}{c}$ in $-\frac{y^{-c}}{c} = kt+C$

$-\frac{y^{-c}}{c} = kt-\frac{y_0^{-c}}{c}$

Multiply through by -c

$y^{-c} = -ckt+y_0^{-c}$

Take exponents of $-c^{-1$

$y^{-c*-c^{-1}} = [-ckt+y_0^{-c}]^{-c^{-1}$

$y = [-ckt+y_0^{-c}]^{-c^{-1}$

$y = [-ckt+y_0^{-c}]^{-\frac{1}{c}}$

i.e.

$y(t) = [-ckt+y_0^{-c}]^{-\frac{1}{c}}$

Next:

$t= 3$ i.e. 3 months

$y_0 = 2$ --- initial number of breeds

So, we have:

$y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}$

-----------------------------------------------------------------------------

We have the growth term to be: $ky^{1.01}$

This implies that:

$ky^{1.01} = ky^{1+c}$

By comparison:

$1.01 = 1 + c$

$c = 1.01 - 1 = 0.01$

$y(3) = 16$ --- 16 rabbits after 3 months:

-----------------------------------------------------------------------------

$y(3) = [-ck * 3+2^{-c}]^{-\frac{1}{c}}$

$16 = [-0.01 * 3 * k + 2^{-0.01}]^{\frac{-1}{0.01}}$

$16 = [-0.03 * k + 2^{-0.01}]^{-100}$

$16 = [-0.03 k + 0.9931]^{-100}$

Take -1/100th root of both sides

$16^{-1/100} = -0.03k + 0.9931$

$0.9727 = -0.03k + 0.9931$

$0.03k= - 0.9727 + 0.9931$

$0.03k= 0.0204$

$k= \frac{0.0204}{0.03}$

$k= 0.68$

Recall that:

$-\frac{y^{-c}}{c} = kt+C$

This implies that:

$\frac{y_0^{-c}}{c} = kT$

Make T the subject

$T = \frac{y_0^{-c}}{kc}$

Substitute: $k= 0.68$ , $c = 0.01$ and $y_0 = 2$

$T = \frac{2^{-0.01}}{0.68 * 0.01}$

$T = \frac{2^{-0.01}}{0.0068}$

$T = \frac{0.9931}{0.0068}$

$T = 146.04$

The doomsday is 146 days

4 0

3 years ago

Question 14 of 25

babunello [35]

Using the function concept, it is found that the correct option is:

C. Yes; the graph passes the vertical line test.

In a function, one value of the input can be related to only one value of the output.

In a graph, it means that for each value of x(horizontal axis), there can only be one respective value of y(vertical axis). If it happens, it means that the graph passes the vertical line test.

In this graph, for each value of x, there is only one value of y, hence it passes the vertical line test, and option C is correct.

You can learn more about the function concept at brainly.com/question/12463448

7 0

2 years ago

F(x) = 3x+1 and f ^-1 = x-1/3

Lostsunrise [7]

They are inverses of one another; is there an actual question there somewhere?

8 0

3 years ago