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3 years ago

How do you do this question please help me

Mathematics

1 answer:

Varvara68 [4.7K]3 years ago

8 0

Well then you just do 15-6 right?

whats so hard bout this question?

brainliest would help

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How the heck do I do this? And what’s the answer?

stira [4]

Answer:

Option A

Step-by-step explanation:

We need to find two expressions that, when simplified, give the same results.

1) First, simplify the expression stated in the question. Multiply each of the terms in the parentheses by the number that is next to them. This would mean you have to multiply both 9x and -6 by $\frac{2}{3}$ . You also have to multiply $\frac{1}{2}x$ and $-\frac{1}{2}$ by 4. Then, simplify.

$\frac{2}{3}(9x-6) + 4 (\frac{1}{2} x - \frac{1}{2})\\\frac{18}{3}x- \frac{12}{3} + \frac{4}{2}x -\frac{4}{2} \\6x - 4 + 2x - 2$

2) Now, combine the like terms.

$6x - 4 + 2x - 2$

$8x - 6$

So, we need to find which of the expressions listed equal 8x - 6.

3) Let's try option A. Do the same as before. Multiply each of the terms in the parentheses by the number that is next to them. So, multiply 4x and -12 by $\frac{3}{4}$ . Also, multiply 30x and 18 by $\frac{1}{6}$ . Then, combine like terms and simplify.

$\frac{3}{4} (4x-12) + \frac{1}{6}(30x + 18)\\\frac{12}{4}x-\frac{36}{4} + \frac{30}{6} x + \frac{18}{6} \\3x - 9 + 5x + 3 \\8x - 6$

This also equals 8x - 6. Therefore, option A is the answer.

5 0

2 years ago

Evaluate the expression when n= -2 5n+30

sammy [17]

Answer:

Step-by-step explanation:

5(-2)+30 = (-10)+30 = 20

6 0

2 years ago

Read 2 more answers

In a survey of market, it is found that 143 persons use white toothpaste and 135 use red toothpaste. If 70 of them use both the

denpristay [2]

Answer:

let W and R represent white toothpaste and red toothpaste represently

n(W)=143

n(R)=135

n(WnR)=70

n( WuR)=?

Now,

n(WuR)=n(W)+n(R)_n(WnR)

=143+135_70

=208

that's all don't forget to write therefore.

6 0

2 years ago

Only question numer 10.

leva [86]

Out of the six, only “u” wouldn’t work so the answer is d. 5

Hope this helps and hope you have a great day! Please make brainiest

4 0

2 years ago

Read 2 more answers

Evaluate the surface integral S F · dS for the given vector field F and the oriented surface S. In other words, find the flux of

Tomtit [17]

Apparently my answer was unclear the first time?

The flux of F across S is given by the surface integral,

$\displaystyle\iint_S\mathbf F\cdot\mathrm d\mathbf S$

Parameterize S by the vector-valued function r(u, v) defined by

$\mathbf r(u,v)=7\cos u\sin v\,\mathbf i+7\sin u\sin v\,\mathbf j+7\cos v\,\mathbf k$

with 0 ≤ u ≤ π/2 and 0 ≤ v ≤ π/2. Then the surface element is

dS = n • dS

where n is the normal vector to the surface. Take it to be

$\mathbf n=\dfrac{\frac{\partial\mathbf r}{\partial v}\times\frac{\partial\mathbf r}{\partial u}}{\left\|\frac{\partial\mathbf r}{\partial v}\times\frac{\partial\mathbf r}{\partial u}\right\|}$

The surface element reduces to

$\mathrm d\mathbf S=\mathbf n\,\mathrm dS=\mathbf n\left\|\dfrac{\partial\mathbf r}{\partial u}\times\dfrac{\partial\mathbf r}{\partial v}\right\|\,\mathrm du\,\mathrm dv$

$\implies\mathbf n\,\mathrm dS=-49(\cos u\sin^2v\,\mathbf i+\sin u\sin^2v\,\mathbf j+\cos v\sin v\,\mathbf k)\,\mathrm du\,\mathrm dv$

so that it points toward the origin at any point on S.

Then the integral with respect to u and v is

$\displaystyle\iint_S\mathbf F\cdot\mathrm d\mathbf S=\int_0^{\pi/2}\int_0^{\pi/2}\mathbf F(x(u,v),y(u,v),z(u,v))\cdot\mathbf n\,\mathrm dS$

$=\displaystyle-49\int_0^{\pi/2}\int_0^{\pi/2}(7\cos u\sin v\,\mathbf i-7\cos v\,\mathbf j+7\sin u\sin v\,\mathbf )\cdot\mathbf n\,\mathrm dS$

$=-343\displaystyle\int_0^{\pi/2}\int_0^{\pi/2}\cos^2u\sin^3v\,\mathrm du\,\mathrm dv=\boxed{-\frac{343\pi}6}$

4 0

3 years ago