order of operation algorithm (-9)(-20)/(-5)(4)=?

(-9)(-20)/(-5)(4)=
(+180)/(-20)=
-9

There is really no specific order and question may be done in a number of different ways.

(-9) (-20)
------------
(-5) (4)

(-9) (-5)
---------
(-5)

- 9

OR

(-9)(-20)
-----------
(-5) (4)

180
-------
- 20

- 9

OR

(-9) (-20)
----------
(-5) (4)

(-9) (4)
-----------
(4)

- 9

Everyone is wrong xD
mult. and div. have the same precedence, and if they appear at the same time, they are used from left to right. One guy was right about this but got it wrong (144 instead of -144)

(-9)(-20)/(-5)(4)
(180)/(-5)(4)
(-36)(4)
(-144)

The mnemonic for remembering the order of operations that I learned is:

*P*lease *E*xcuse *M*y *D*ear *A*unt *S*ally.

The first letters of each word mean:

Parentheses (highest precedence, work through them first)

Exponents

Multiplication

Division

Addition

Subtraction (lowest precedence, do last)


In this case, the parentheses don't do much since they each contain single numbers.

Since there are no exponents, the first thing to be done is to work out any multiplications. There are two of them to do: -9 times -20 and -5 times 4.

Doing that leaves 180 to be divided by -20 which gives you the final answer of -9.

(-9)(-20)/(-5)(4)
= 180/-20
= -9

From Wkipedia's Order of Operations:
"It is usual, wherever you need to calculate operations of equal precedence to work from left to right. "

With multiplication and division being equal priority, the calculations proceed from left to right,so:

step1. (-9)*(-20) = (-180)
step2. (-180)/(-5) = (36)
step3. (36)*(4) = 144

Ans: 144

Hope that helps.