All categories

3 years ago

-y (2 - 5y + 4) Simplify plz

Mathematics

2 answers:

Snezhnost [94]3 years ago

6 0

Answer:

Step-by-step explanation:

-y(2 - 5y + 4)

Opening bracket

= -2y + 5y² + 4y

= 5y² + 2y

Neko [114]3 years ago

3 0

This equation simplified would be

-y(-5y+6)

You might be interested in

<img src="https://tex.z-dn.net/?f=6%20-%202x%20-%204%282x%20%2B%201%29" id="TexFormula1" title="6 - 2x - 4(2x + 1)" alt="6 - 2x

Elanso [62]

You should use photo math it helps a lot

5 0

2 years ago

Read 2 more answers

an inlet pipe and a hose together can fill the pond in 10 hours. The inlet pipe alone can complete the job in one hour less time

Annette [7]

Answer:

The hose pipe can fill the pond in 21.465 hours.

The inlet pipe can fill the pond in 20.465 hours.

Step-by-step explanation:

Given that, a inlet pipe and a hose pipe together can fill the pond in 10 hours.

The inlet pipe alone can fill the pond in one hour less time than the hose pipe can fill the pond.

Let the hose pipe can complete the job in x hours.

Then the inlet pipe can fill the pond in (x-1) hours.

The rate of filling of hose pipe is $=\frac{1}{x}$

The rate of filling of inlet pipe is $=\frac{1}{x-1}$

The rate of filling of both pipes is = $\frac 1{10}$

According to the problem,

$\frac{1}{x}+\frac{1}{x-1}=\frac{1}{10}$

$\Rightarrow \frac{x-1+x}{x(x-1)}=\frac1{10}$ [ simplifying the fraction]

$\Rightarrow \frac{2x-1}{x^2-x}=\frac1{10}$

$\Rightarrow 10(2x-1)= x^2-x$ [ Multiplying 10(x²-x) both sides]

$\Rightarrow x^2-x= 20x-10$

$\Rightarrow x^2-x-20x+10=0$ [ simplifying ]

$\Rightarrow x^2-21x+10=0$

$\Rightarrow x=\frac{-(-21)\pm\sqrt{(-21)^2-4.1.10}}{2.1}$ [ applying quadratic formula]

$\Rightarrow x=\frac{21\pm21.93}{2.1}$

⇒ x= 21.465, -0.465

x= - 0.465 does not possible, since time can not be negative.

∴x=21.465

The hose pipe can fill the pond in 21.465 hours.

The inlet pipe can fill the pond in (21.465-1)=20.465 hours.

3 0

3 years ago

Sal owns a clothing store that sells shorts and graphic T-shirts. He sells the

oee [108]

Answer:

You have a thing on there saying the answer is c. If you got the answer there is no point of asking it.

7 0

3 years ago

The wind speed in mph was measured every six hours

valentina_108 [34]

Answer:

25 transwind

Step-by-step explanation:

the wind speed in your country is probably 4cm and in the next six hours is going to change to carbon dioxide speed which is 25 transpiring

6 0

3 years ago

Find the exact value of the expression.<br> tan( sin−1 (2/3)− cos−1(1/7))

Sonja [21]

Answer:

$\tan(a-b)=\frac{2\sqrt{5}-20\sqrt{3}}{5+8\sqrt{15}}$

Step-by-step explanation:

I'm going to use the following identity to help with the difference inside the tangent function there:

$\tan(a-b)=\frac{\tan(a)-\tan(b)}{1+\tan(a)\tan(b)}$

Let $a=\sin^{-1}(\frac{2}{3})$ .

With some restriction on $a$ this means:

$\sin(a)=\frac{2}{3}$

We need to find $\tan(a)$ .

$\sin^2(a)+\cos^2(a)=1$ is a Pythagorean Identity I will use to find the cosine value and then I will use that the tangent function is the ratio of sine to cosine.

$(\frac{2}{3})^2+\cos^2(a)=1$

$\frac{4}{9}+\cos^2(a)=1$

Subtract 4/9 on both sides:

$\cos^2(a)=\frac{5}{9}$

Take the square root of both sides:

$\cos(a)=\pm \sqrt{\frac{5}{9}}$

$\cos(a)=\pm \frac{\sqrt{5}}{3}$

The cosine value is positive because $a$ is a number between $-\frac{\pi}{2}$ and $\frac{\pi}{2}$ because that is the restriction on sine inverse.

So we have $\cos(a)=\frac{\sqrt{5}}{3}$ .

This means that $\tan(a)=\frac{\frac{2}{3}}{\frac{\sqrt{5}}{3}}$ .

Multiplying numerator and denominator by 3 gives us:

$\tan(a)=\frac{2}{\sqrt{5}}$

Rationalizing the denominator by multiplying top and bottom by square root of 5 gives us:

$\tan(a)=\frac{2\sqrt{5}}{5}$

Let's continue on to letting $b=\cos^{-1}(\frac{1}{7})$ .

Let's go ahead and say what the restrictions on $b$ are.

$b$ is a number in between 0 and $\pi$ .

So anyways $b=\cos^{-1}(\frac{1}{7})$ implies $\cos(b)=\frac{1}{7}$ .

Let's use the Pythagorean Identity again I mentioned from before to find the sine value of $b$ .

$\cos^2(b)+\sin^2(b)=1$

$(\frac{1}{7})^2+\sin^2(b)=1$

$\frac{1}{49}+\sin^2(b)=1$

Subtract 1/49 on both sides:

$\sin^2(b)=\frac{48}{49}$

Take the square root of both sides:

$\sin(b)=\pm \sqrt{\frac{48}{49}$

$\sin(b)=\pm \frac{\sqrt{48}}{7}$

$\sin(b)=\pm \frac{\sqrt{16}\sqrt{3}}{7}$

$\sin(b)=\pm \frac{4\sqrt{3}}{7}$

So since $b$ is a number between $0$ and $\pi$ , then sine of this value is positive.

This implies:

$\sin(b)=\frac{4\sqrt{3}}{7}$

So $\tan(b)=\frac{\sin(b)}{\cos(b)}=\frac{\frac{4\sqrt{3}}{7}}{\frac{1}{7}}$ .

Multiplying both top and bottom by 7 gives:

$\frac{4\sqrt{3}}{1}= 4\sqrt{3}$ .

Let's put everything back into the first mentioned identity.

$\tan(a-b)=\frac{\tan(a)-\tan(b)}{1+\tan(a)\tan(b)}$

$\tan(a-b)=\frac{\frac{2\sqrt{5}}{5}-4\sqrt{3}}{1+\frac{2\sqrt{5}}{5}\cdot 4\sqrt{3}}$

Let's clear the mini-fractions by multiply top and bottom by the least common multiple of the denominators of these mini-fractions. That is, we are multiplying top and bottom by 5:

$\tan(a-b)=\frac{2 \sqrt{5}-20\sqrt{3}}{5+2\sqrt{5}\cdot 4\sqrt{3}}$

$\tan(a-b)=\frac{2\sqrt{5}-20\sqrt{3}}{5+8\sqrt{15}}$

4 0

3 years ago