Use compatible numbers to complete the problem. Then estimate the difference 57-21

HELP ME WITH THIS! 1/3 a = 7/9

andreyandreev [35.5K]

Answer:

a = 2 $\frac{1}{3}$

Step-by-step explanation:

Given

$\frac{1}{3}$ a = $\frac{7}{9}$

Multiply both sides by 9 ( the LCM of 3 and 9 ) to clear the fractions

3a = 7 ( divide both sides by 3 )

a = $\frac{7}{3}$ = 2 $\frac{1}{3}$

6 0

3 years ago

Read 2 more answers

Given m|n, find the value of x. t m (9x+23) (10x+6)° Someone help?

Mashutka [201]

Since M is parallel to N that means they would have to equal each other.

6 0

3 years ago

Arlette sold half of her 32 CDs and then bought twenty more. How many CDs does she have now?

anyanavicka [17]

Answer:

36 CDs

Step-by-step explanation:

32/2=16

16+20

36 CDs is your answer. Have a nice day!

6 0

3 years ago

Find the directional derivative of the function at the given point in the direction of the vector v. h(r, s, t) = ln(3r + 6s + 9

vodka [1.7K]

Answer:

$D_\overrightarrow{\rm v}$ $h(r,s,t)=(\frac{2}{7}\overrightarrow{\rm i})*(\frac{1}{r+2s+3t})+(\frac{6}{7}\overrightarrow{\rm j})*(\frac{2}{r+2s+3t})+(\frac{3}{7}\overrightarrow{\rm k})*(\frac{3}{r+2s+3t})$

Step-by-step explanation:

First, let’s check to see if the direction vector is a unit vector:

$||v||=\sqrt{(14)^{2} +(42)^{2} +(21)^{2} } =\sqrt{2401} =49$

It’s not a unit vector. therefore let's divide the vector by its magnitude in order to convert it into a unit vector:

$\overrightarrow{\rm v}=(\frac{14}{49}\overrightarrow{\rm i})+(\frac{42}{49}\overrightarrow{\rm j})+(\frac{21}{49}\overrightarrow{\rm k})= (\frac{2}{7}\overrightarrow{\rm i})+(\frac{6}{7}\overrightarrow{\rm j})+(\frac{3}{7}\overrightarrow{\rm k})$

Now, the directional derivative is given by:

$D_\overrightarrow{\rm v}$ $h(r,s,t)=\frac{\partial h(r,s,t)}{\partial r}\overrightarrow{\rm i} + \frac{\partial h(r,s,t)}{\partial s}\overrightarrow{\rm j} + \frac{\partial h(r,s,t)}{\partial t}\overrightarrow{\rm k}$

So let's calculate the partial derivates:

$\frac{\partial }{\partial r} ln(3r+6s+9t)=\frac{3}{3r+6s+9t}=\frac{1}{r+2s+3t}$

$\frac{\partial }{\partial s} ln(3r+6s+9t)=\frac{6}{3r+6s+9t}=\frac{2}{r+2s+3t}$

$\frac{\partial }{\partial t} ln(3r+6s+9t)=\frac{9}{3r+6s+9t}=\frac{3}{r+2s+3t}$

Therefore:

$D_\overrightarrow{\rm v}$ $h(r,s,t)=(\frac{2}{7}\overrightarrow{\rm i})*(\frac{1}{r+2s+3t})+(\frac{6}{7}\overrightarrow{\rm j})*(\frac{2}{r+2s+3t})+(\frac{3}{7}\overrightarrow{\rm k})*(\frac{3}{r+2s+3t})$

3 0

3 years ago

Please help! I need this done extremely quickly! questions 17-20

Zolol [24]

Answer:

-3

Step-by-step explanation:

use a calculator becuase thats so easy

4 0

3 years ago