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3 years ago

7x-8(-2x+9)=112 What is x

Mathematics

2 answers:

zaharov [31]3 years ago

8 0

Okay so first you need to combine like terms

alex41 [277]3 years ago

3 0

(8, -2) here is your answer

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Need the answer..Anyone know?

hodyreva [135]

You need to show us the figure so we can tell you.

4 0

3 years ago

Find dy/dx by implicit differentiation for ysin(y) = xcos(x)

tatyana61 [14]

Answer:

$\frac{dy}{dx}=\frac{\cos(x)-x\sin(x)}{\sin(y)+y\cos(y)}$

Step-by-step explanation:

So we have:

$y\sin(y)=x\cos(x)$

And we want to find dy/dx.

So, let's take the derivative of both sides with respect to x:

$\frac{d}{dx}[y\sin(y)]=\frac{d}{dx}[x\cos(x)]$

Let's do each side individually.

Left Side:

We have:

$\frac{d}{dx}[y\sin(y)]$

We can use the product rule:

$(uv)'=u'v+uv'$

So, our derivative is:

$=\frac{d}{dx}[y]\sin(y)+y\frac{d}{dx}[\sin(y)]$

We must implicitly differentiate for y. This gives us:

$=\frac{dy}{dx}\sin(y)+y\frac{d}{dx}[\sin(y)]$

For the sin(y), we need to use the chain rule:

$u(v(x))'=u'(v(x))\cdot v'(x)$

Our u(x) is sin(x) and our v(x) is y. So, u'(x) is cos(x) and v'(x) is dy/dx.

So, our derivative is:

$=\frac{dy}{dx}\sin(y)+y(\cos(y)\cdot\frac{dy}{dx}})$

Simplify:

$=\frac{dy}{dx}\sin(y)+y\cos(y)\cdot\frac{dy}{dx}}$

And we are done for the right.

Right Side:

We have:

$\frac{d}{dx}[x\cos(x)]$

This will be significantly easier since it's just x like normal.

Again, let's use the product rule:

$=\frac{d}{dx}[x]\cos(x)+x\frac{d}{dx}[\cos(x)]$

Differentiate:

$=\cos(x)-x\sin(x)$

So, our entire equation is:

$=\frac{dy}{dx}\sin(y)+y\cos(y)\cdot\frac{dy}{dx}}=\cos(x)-x\sin(x)$

To find our derivative, we need to solve for dy/dx. So, let's factor out a dy/dx from the left. This yields:

$\frac{dy}{dx}(\sin(y)+y\cos(y))=\cos(x)-x\sin(x)$

Finally, divide everything by the expression inside the parentheses to obtain our derivative:

$\frac{dy}{dx}=\frac{\cos(x)-x\sin(x)}{\sin(y)+y\cos(y)}$

And we're done!

5 0

3 years ago

What kind of number is -2

makvit [3.9K]

Is a number negative

5 0

4 years ago

What is the simplified form of the equation 4/5n - 1/5 = 2/5n ?

Gnoma [55]

we are given

$\frac{4}{5}n -\frac{1}{5} =\frac{2}{5}n$

Firstly , we will multiply both sides by 5

$5*\frac{4}{5}n -5*\frac{1}{5} =5*\frac{2}{5}n$

now, we can simplify it

$4n-1 =2n$

$2n =1$

now, we can solve for n

$n =\frac{1}{2}$ .............Answer

8 0

4 years ago

Bob can mow 3 lawns in 5 hours. How long would it take it to mow 9 lawns?

olga2289 [7]

Answer:

15 hours

Step-by-step explanation:

9 lawns is 3 times as much as 3 lawns

it will take 3 times as long

3 * 5 hours = 15 hours

3 0

3 years ago