Calla bought 8 writing utensils for a total of $30. Pens cost $4 each and pencils cost $3 each. How many pens did she buy?

Is 1/9+1/8 closer to 0.5 or 1/2? explain.

xenn [34]

Answer:

Well 0.5 is the same as 1/2 but I'll try to help.

Step-by-step explanation:

1/9+1/8 is 0.2361. That would honestly be closer to zero but the way that it is worded, it is closer to 1/2 because you are using fractions in the problem. If you were using decimals, I would use 0.5

5 0

2 years ago

Find the derivative

zalisa [80]

First use the chain rule; take $y=\dfrac{x+5}{x^2+3}$ . Then

$\dfrac{\mathrm df}{\mathrm dx}=\dfrac{\mathrm df}{\mathrm dy}\cdot\dfrac{\mathrm dy}{\mathrm dx}$

By the power rule,

$f(x)=y^2\implies\dfrac{\mathrm df}{\mathrm dy}=2y=\dfrac{2(x+5)}{x^2+3}$

By the quotient rule,

$y=\dfrac{x+5}{x^2+3}\implies\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{(x^2+3)\frac{\mathrm d(x+5)}{\mathrm dx}-(x+5)\frac{\mathrm d(x^2+3)}{\mathrm dx}}{(x^2+3)^2}$

$\implies\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{(x^2+3)-(x+5)(2x)}{(x^2+3)^2}$

$\implies\dfrac{\mathrm dy}{\mathrm dx}=\dfrac{3-10x-x^2}{(x^2+3)^2}$

So

$\dfrac{\mathrm df}{\mathrm dx}=\dfrac{2(x+5)}{x^2+3}\cdot\dfrac{3-10x-x^2}{(x^2+3)^2}$

$\implies\dfrac{\mathrm df}{\mathrm dx}=\dfrac{2(x+5)(3-10x-x^2)}{(x^2+3)^3}$

6 0

2 years ago

Solve the differential equation dy dx equals the quotient of x squared and y squared for y = f(x) with the initial condition y(0

Gnoma [55]

$\displaystyle\frac{dy}{dx} = \frac{x^2}{y^2}\ \Rightarrow\ y^2 dy = x^2 dx\ \Rightarrow\ \int y^2 dy = \int x^2 dx\ \Rightarrow\textstyle\ \frac{1}{3}y^3 = \frac{1}{3}x^3 + C. \\ \\
\text{Now } y(0) = 2\ \Rightarrow\ \frac{1}{3}(2)^3 = \frac{1}{3}(0)^3 + C\ \Rightarrow\ \frac{8}{3} = C,\text{ so } \frac{1}{3}y^3 = \frac{1}{3}x^3 + \frac{8}{3}. \\ \\
y^3 = x^3 + 8\ \Rightarrow\ y = \sqrt[3]{x^3 + 8}$

7 0

2 years ago

When converted to a household measurement, 9 kilograms is approximately equal to a

a_sh-v [17]

Abt 317.4 oz or 19.4 lb

5 0

2 years ago

Read 2 more answers

Someone please Solve 3 (x - 1) = 6. Thank you

kramer

We have an equation with parentheses. To make our lives easier, first get rid of the parentheses. We do this by using the distributive property.

It is used like this: a(b + c) = ab + ac.

Use the distributive property on the left-hand side.

3(x - 1) = 6
3x - 3 = 6

Now we have an equation that is easier.

The x variable is being multiplied by 3 and added to -3.
Reverse all of these operations with their inverse operation.

3x - 3 = 6
3x = 9 <--- I got rid of the -3 term by using the inverse of subtraction. Addition.
And I did the same for both sides to keep the equation true.
x = 3 <--- The inverse of multiplication is division.
So, I divided both sides by 3.

So, x is equal to 3.

3 0

3 years ago