All categories

1 year ago

-9x²(x²+2x²y - 3y²) Simplify

Mathematics

2 answers:

yKpoI14uk [10]1 year ago

4 0

<h2>Your answer is:</h2>

−9x^4−18x^4y+27x^2y^2

Dvinal [7]1 year ago

3 0

Answer:

=−18x^4y−9x^4+27x^2y^2

Step-by-step explanation:

(−9x^2)(x^2+2x^2y−3y^2)

=(−9x^2)(x^2+2x^2y+−3y^2)

=(−9x^2)(x^2)+(−9x^2)(2x^2y)+(−9x^2)(−3y^2)

=−9x^4−18x^4y+27x^2y^2

=−18x^4y−9x^4+27x^2y^2

---

Hope I helped! Have a great day :)

Read more about rate of change at:

brainly.com/question/8728504

4 0

2 years ago

Kryptonite is a material found on the planet Krypton and has various effects, most importantly on Superman. The most common type

Rashid [163]

Answer:

The maximum amount of red kryptonite present is 33.27 g after 4.93 hours.

Step-by-step explanation:

dy/dt = y(1/t - k)

separating the variables, we have

dy/y = (1/t - k)dt

dy/y = dt/t - kdt

integrating both sides, we have

∫dy/y = ∫dt/t - ∫kdt

㏑y = ㏑t - kt + C

㏑y - ㏑t = -kt + C

㏑(y/t) = -kt + C

taking exponents of both sides, we have

$\frac{y}{t} = e^{-kt + C} \\\frac{y}{t} = e^{-kt}e^{C} \\\frac{y}{t} = Ae^{-kt} (A = e^{C})\\y = Ate^{-kt}$

when t = 1 hour, y = 15 grams. So,

$y = Ate^{-kt}\\15 = A(1)e^{-kX1}\\15 = Ae^{-k}$ (1)

when t = 3 hours, y = 30 grams. So,

$y = Ate^{-kt}\\30 = A(3)e^{-kX3}\\30 = 3Ae^{-3k}$ (2)

dividing (2) by (1), we have

$\frac{30}{15} = \frac{3Ae^{-3k}}{Ae^{-k}} \\2 = 3e^{-2k}\\\frac{2}{3} = e^{-2k}$

taking natural logarithm of both sides, we have

-2k = ㏑(2/3)

-2k = -0.4055

k = -0.4055/-2

k = 0.203

From (1)

$A = 15e^{k} \\A = 15e^{0.203} \\A = 15 X 1.225\\A = 18.36$

Substituting A and k into y, we have

$y = 18.36te^{-0.203t}$

The maximum value of y is obtained when dy/dt = 0

dy/dt = y(1/t - k) = 0

y(1/t - k) = 0

Since y ≠ 0, (1/t - k) = 0.

So, 1/t = k

t = 1/k

So, the maximum value of y is obtained when t = 1/k = 1/0.203 = 4.93 hours

$y = 18.36(1/0.203)e^{-0.203t}\\y = \frac{18.36}{0.203}e^{-0.203X1/0.203}\\y = 90.44e^{-1}\\y = 90.44 X 0.3679\\y = 33.27 g$

<u>So the maximum amount of red kryptonite present is 33.27 g after 4.93 hours.</u>

3 0

2 years ago

Solve the inequality 5u≤8u−21 and write the solution in interval notation

PIT_PIT [208]

Answer:

Step-by-step explanation:

$5u\leq 8u-21$

Subtract 8u from both sides

$-3u\leq -21$

Divide by -3 on both sides

$u\geq 7$

Interval notation: [greater/less than or equal to], (greater or equal to)

[7,∞)

3 0

2 years ago

Write -12 7/8 as a decimal. (NEED ASAP WITH WORK)

seropon [69]

7/8 can be converted to .875 because 1/8 is .125 and .125*7=.875. Add -12 to it so the answer is -12.875

5 0

2 years ago

Choose all true statements.

serious [3.7K]

Answer:

Some rational numbers are natural numbers

All whole numbers are integers

Some integers are natural numbers.

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers