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3 years ago

Please help, and please give me an explanation.

Mathematics

1 answer:

vichka [17]3 years ago

7 0

I Believe that it is not the last 3 Answers.

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Subtract. 5x – 6x+2 - 1-2x - x - 2)

adell [148]

Answer:

7x^2 -5x + 4

Step-by-step explanation:

5x^2 – 6x+2

- (-2x^2 - x - 2)

We got 5x^2 - (-2x^2) = 5x^2 + 2x^2 = 7x^2

-6x - (-x) = -6x + x = -5x

2 - (-2) = 2+2 = 4

So the equation would be 7x^2 -5x + 4

Hope this help :3

3 0

2 years ago

Which equation has no solution? |-x - 3| = 5 |2x – 1| =0 |15 - 3x|= -8 |-x + 9| = 0

djverab [1.8K]

Answer:

the last one

Step-by-step explanation:

5 0

2 years ago

Use Simpson's Rule with n = 10 to approximate the area of the surface obtained by rotating the curve about the x-axis. Compare y

DiKsa [7]

The area of the surface is given exactly by the integral,

$\displaystyle\pi\int_0^5\sqrt{1+(y'(x))^2}\,\mathrm dx$

We have

$y(x)=\dfrac15x^5\implies y'(x)=x^4$

so the area is

$\displaystyle\pi\int_0^5\sqrt{1+x^8}\,\mathrm dx$

We split up the domain of integration into 10 subintervals,

[0, 1/2], [1/2, 1], [1, 3/2], ..., [4, 9/2], [9/2, 5]

where the left and right endpoints for the $i$ -th subinterval are, respectively,

$\ell_i=\dfrac{5-0}{10}(i-1)=\dfrac{i-1}2$

$r_i=\dfrac{5-0}{10}i=\dfrac i2$

with midpoint

$m_i=\dfrac{\ell_i+r_i}2=\dfrac{2i-1}4$

with $1\le i\le10$ .

Over each subinterval, we interpolate $f(x)=\sqrt{1+x^8}$ with the quadratic polynomial,

$p_i(x)=f(\ell_i)\dfrac{(x-m_i)(x-r_i)}{(\ell_i-m_i)(\ell_i-r_i)}+f(m_i)\dfrac{(x-\ell_i)(x-r_i)}{(m_i-\ell_i)(m_i-r_i)}+f(r_i)\dfrac{(x-\ell_i)(x-m_i)}{(r_i-\ell_i)(r_i-m_i)}$

Then

$\displaystyle\int_0^5f(x)\,\mathrm dx\approx\sum_{i=1}^{10}\int_{\ell_i}^{r_i}p_i(x)\,\mathrm dx$

It turns out that the latter integral reduces significantly to

$\displaystyle\int_0^5f(x)\,\mathrm dx\approx\frac56\left(f(0)+4f\left(\frac{0+5}2\right)+f(5)\right)=\frac56\left(1+\sqrt{390,626}+\dfrac{\sqrt{390,881}}4\right)$

which is about 651.918, so that the area is approximately $651.918\pi\approx\boxed{2048}$ .

Compare this to actual value of the integral, which is closer to 1967.

4 0

3 years ago

Evaluate -2/5-4/5+(-9/10)

Sphinxa [80]

ANSWER-

- 21/10 or -2.1

4 0

3 years ago

Solve for x and y

BigorU [14]

You can use elimination
7x - 3y = 4
-10x + 3y = 2
Add both equations
-3x = 6, x = -2
Plug in -2 for x in one equation
7(-2) - 3y = 4
-14 - 3y = 4
-3y = 18, y = -6
Solution: x = -2, y = -6

4 0

2 years ago