an expression is shown 40 - 20 / 4 / 4 x 2.

Mathematics

1 answer:

BaLLatris [955]3 years ago

7 0

We can use PEMDAS to help us:

P - Parenthesis

E - Exponents

M - Multiplication

D - Division

A - Addition

S - Subtraction

PEMDAS states what occurs first in order of which letter pertains to which mathematical operation and how you are suppose to do it from left to right. Since multiplication and division comes before addition and subtraction, we know C isn't the answer since it is subtraction. This leaves us with A, B, and D. They all happen to be either multiplication and division. Although multiplication SEEMS to come before division, multiplication and division are actually paired together (just like addition and subtraction) meaning that if either a multiplication or division comes before a division and multiplication operation, you do it left to right. For example, 2 x 2/2. You do 2 x 2 first equaling 4 and then divide by 2 to get 2. Another example is 10/2 x 5. You DO NOT do multiplication first since multiplication and division are paired together meaning you do 10/2 equaling 5 and then do 5 x 5 equaling 25. Enough explanation for that part. Since 20/4 is the first multiplication/division operation, that is what you do first. The answer is A.

You might be interested in

Let F ( x , y , z ) = ⟨ x − 1 z , y − 1 z , ln ( x y ) ⟩ . Verify that F = ∇ f , where f ( x , y , z ) = z ln ( x y ) . Evaluate

lesya692 [45]

I suppose you mean

$\vec F(x,y,z)=\left\langle\dfrac zx,\dfrac zy,\ln(xy)\right\rangle$

Showing that $f(x,y,z)=z\ln(xy)$ has gradient equal to $\vec F$ is trivial.

By virtue of the existence of $f$ , the gradient theorem applies here, so

$\displaystyle\int_C\vec F\cdot\mathrm d\vec r=\int_{(12,4,2)}^{(2,2,3)}\nabla f(x,y,z)\cdot\mathrm d\vec r=f(2,2,3)-f(12,4,2)=3\ln 4-2\ln48=\boxed{-\ln36}$

The requirement that $x>0$ and $y>0$ is a consequence of the domain of the logarithm function. Both have to be positive in order for $\ln(xy)$ to exist.

7 0

3 years ago

The answer to the question

bixtya [17]

The picture is too low quality to visualize. Please revise it.

Thanks

3 0

3 years ago

A boat travels 45 miles upstream (against the current) in 5 hours. The boat travels the same distance downstream in 3 hours. Wha

Leona [35]

R=rate of boat in still water
c=rate of current
d=rt
since you're given that the time it takes to travel the same distance downstream and upstream, your equation will be d_1=d_2, or rt=rt
the rate upstream is r-c and the rate downstream is r+c (because the boat's and river's rates add up)
since you know t_1 and t_1 are 5 and 3, you can now set up 2 equations
<u>5*(r-c)=45</u> because (time upstream)*(rate upstream)=distance=45 miles
r-c=45/5=9
<u>3*(r+c)=45</u>
r+c=45/3=15
r-c=9 and r+c=15, so r=12 mi/h and c=3 mi/h
If you have any questions please ask

3 0

3 years ago

100 students take a course pass/fail. If they pass they get 4 points towards their GPA, if they fail they get 0. If 90 students

zheka24 [161]

10 of them fail so 10 of them get 0 and no points to there GPA

4 0

3 years ago

Can someone help me

s2008m [1.1K]