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thank you

3z/10 + 4=-1

what is z???

Solve for z:
(3z)/10+4 = -1

Put each term in (3 z)/10+4 over the common denominator 10: (3 z)/10+4  =  (3 z)/10+40/10:
(3 z)/10+40/10 = -1

(3 z)/10+40/10 = (3 z+40)/10:
(3 z+40)/10 = -1

Multiply both sides of (3 z+40)/10 = -1 by 10:
(10 (3 z+40))/10 = -10

(10 (3 z+40))/10 = 10/10×(3 z+40) = 3 z+40:
Answer: | 
| 3z+40 = -10, z=- 50/3

i dont know how to use the calculater though its confusing

Hello dear Guest, did you know that this website has a calculator for solving such problem? 

- Head over to the "Home" tab, type your equation and try to get the calculator to figure out z for ya!

Good luck, Mormert.

thankyou

35y+4=-1 what is y?

35y=-1-4=-5 divide both sides by 35

y=-5/35=-1/7

y=-1/7

4,9,...,19,.....,.....,34

How about:

4, 9, 14, 19, 24, 29, 34, 39, 44.....................etc

Do you see the pattern? What's the common difference from one term to the next?

9 + 10 = 19.

9 + 10 = 19.

Hallo guest

x²÷y²+y÷x=?

Simplify the following:
x^2/y^2+y/x

Put each term in x^2/y^2+y/x over the common denominator x y^2: x^2/y^2+y/x  =  x^3/(x y^2)+y^3/(x y^2):
x^3/(x y^2)+y^3/(x y^2)

x^3/(x y^2)+y^3/(x y^2) = (x^3+y^3)/(x y^2):
(x^3+y^3)/(x y^2)

Factor the sum of two cubes. x^3+y^3 = (x+y) (x^2-x y+y^2):
Answer: | 
| (x+y) (x^2-x y+y^2)/(xy^2)

You can factorise this but you cannot simplify it.

3^x=29   take the log of each side

log 3^x = log 29   and we can write

x log 3  =  log  29     divide both sides by log 3

x = log 29 / log 3   =  about  3.065

Just let your mind think in maths every day and you may change your opinion. ;)

Ooops....sorry, I had the words FOOD and DRINKS reversed in my original answer (but the math is the same)

Well, what we are looking for is theoriginal amount of money Eric had.....let's call that amount 'x'

He spent 20% of 'x'    or  0.20x   which left him with 80 percent of 'x'  (or 0.8x) after his first purchase of FOOD.

Then he spent 30% of what he had left (80 percent of 'x' ...or 0.8x )

SO for DRINKS he spent  0.3 (0.8x)

and THEN he had only $28 dolllars left.....in equation form this looks like this:

x - 02.x - .3(.8x) = 28    then just solve for 'x'

x - .2x -.24x = 28

x - .44x = 28

.56x = 28      (now divide both sides by .56)

(.56x)/.56  =  28/(.56)

x = 50 dollars

Well

70% of 80% of original is $28

You need to turn this into an equation and then solve it :)

Hint

Let original be X

Well, what we are looking for is theoriginal amount of money Eric had.....let's call that amount 'x'

He spent 20% of 'x'    or  0.20x   which left him with 80 percent of 'x'  (or 0.8x) after his first purchase of drinks.

Then he spent 30% of what he had left (80 percent of 'x' ...or 0.8x )

SO for food he spent  0.3 (0.8x)

and THEN he had only $28 dolllars left.....in equation form this looks like this:

x - 02.x - .3(.8x) = 28    then just solve for 'x'

x - .2x -.24x = 28

x - .44x = 28

.56x = 28      (now divide both sides by .56)

(.56x)/.56  =  28/(.56)

x = 50 dollars

This is by the way a method to figure out the acceleration of a car, for example.

https://youtu.be/FOkQszg1-j8

Check it out!

That helps. I was getting 6.6.

Thank you

I think Guest means how to divide it without a calculator, check this link out:

https://www.youtube.com/watch?v=GyeXuteChFI

This method can be used for larger integers as well.

There is a calc on the home page.  

Off you go, give your fingers some more exercise :)

What do you want to divide it by?

Can't you just put it into the calculator?

If you needto use a formula, this page should explain it ok :)

https://www.mathsisfun.com/data/standard-deviation-formulas.html

Here's a calculator that will do this for you......http://www.alcula.com/calculators/statistics/standard-deviation/

You must specify whether this is a population or a sample.....the results are different, depending upon the assumption....