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3 years ago

EXPAND it please and explain (9r-s/7)(9r+s/7)

Mathematics

1 answer:

Mars2501 [29]3 years ago

4 0

Answer:

2. 2

81r - s/49

Step-by-step explanation: I don’t know how to explain it but yeah

( I’m probably wrong so if I am I’m sorry)

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It’s MrBeast what’s 600+1 I’ll make brainliest.

Sonbull [250]

Answer:

601

Step-by-step explanation:

Hmm... That question took me years to solve.

8 0

2 years ago

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The amount in kilograms, a, of a radioactive element that remains after t hours can be modeled by the equation a= 0.65(0.92)to t

elena-14-01-66 [18.8K]

Answer:

The rate of decrease is 8%

Step-by-step explanation:

we know that

The general equation for the radioactive decay can be written as:

$a=a_0(1-r)^t$

where

a is the amount in kilograms after time t.

a_0 is the original amount of the substance or y-intercept of the function

r is the decay rate, written in decimals.

t is the time

In this problem we have

$a=0.65(0.92)^t$

$a_0=0.65\\(1-r)=0.92$

solve for r

$r=1-0.92=0.08$

Convert to percentage

$0.08(100)=8\%$

6 0

3 years ago

Write an expression, using an exponent that is equivalent to 6 x 6 x 6 x 6 x 6.

valentinak56 [21]

Answer:

6^5

Step-by-step explanation:

put the 5 and make it tiny on top of the 6

3 0

2 years ago

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Find the length of the following curve. If you have a grapher, you may want to graph the curve to see what it looks like.

stepladder [879]

The length of the curve $y = \frac{1}{27}(9x^2 + 6)^\frac 32$ from x = 3 to x = 6 is 192 units

<h3>How to determine the length of the curve?</h3>

The curve is given as:

$y = \frac{1}{27}(9x^2 + 6)^\frac 32$ from x = 3 to x = 6

Start by differentiating the curve function

$y' = \frac 32 * \frac{1}{27}(9x^2 + 6)^\frac 12 * 18x$

Evaluate

$y' = x(9x^2 + 6)^\frac 12$

The length of the curve is calculated using:

$L =\int\limits^a_b {\sqrt{1 + y'^2}} \, dx$

This gives

$L =\int\limits^6_3 {\sqrt{1 + [x(9x^2 + 6)^\frac 12]^2}\ dx$

Expand

$L =\int\limits^6_3 {\sqrt{1 + x^2(9x^2 + 6)}\ dx$

This gives

$L =\int\limits^6_3 {\sqrt{9x^4 + 6x^2 + 1}\ dx$

Express as a perfect square

$L =\int\limits^6_3 {\sqrt{(3x^2 + 1)^2}\ dx$

Evaluate the exponent

$L =\int\limits^6_3 {3x^2 + 1} \ dx$

Differentiate

$L = x^3 + x|\limits^6_3$

Expand

L = (6³ + 6) - (3³ + 3)

Evaluate

L = 192

Hence, the length of the curve is 192 units