# Math Help - simplify each expression

1. ## simplify each expression

3 dot 5+3 dot 15

5 dot 22-5 dot 2

2. Originally Posted by dianna
3 dot 5+3 dot 15

5 dot 22-5 dot 2
Hello, Dianna,

a) first multiply, then add:

$3 \cdot 5+3 \cdot 15=15+45=60$

b) first multiply, then subtract:

$5 \cdot 22-5 \cdot 2=110-10=100$

EB

3. may i ask.. what does the "dot" represent? is it "." ?

4. Yes does it mean decimal or multiply?

5. Originally Posted by janvdl
Yes does it mean decimal or multiply?
i believe it's multiply, if it was to represent a decimal point she would have just typed "."

6. You never know.

7. Originally Posted by dianna
3 dot 5+3 dot 15

5 dot 22-5 dot 2
3 dot 5+3 dot 15=6 dot 65
5 dot 22-5 dot 2=0 dot 02

8. Originally Posted by lancemaria
3 dot 5+3 dot 15=6 dot 65
5 dot 22-5 dot 2=0 dot 02
we still are not sure what dianna was using the dots to mean. if she meant multiply, earboth is correct, if she meant decimal points, then you are correct...only time will tell it seems

9. ## hello

hi all,
earboth you right.
I think , and maybe all that dot or period in math part that would be meant as multiply.
3 dot 5+3 dot 15
or
3(5) + 3(15) = 60

5 dot 22-5 dot 2
or
5(22) - 5(2) = 100

First you perform multiplication before you can add, as MDAS

10. Originally Posted by lancemaria
First you perform multiplication before you can add, as MDAS
I'm assuming you're using MDAS to represent the order in which you must process an equation?
M - Multiply
D - Divide
S - Subtraction

It should, in fact, be Divide first and then Multiply; ie, DMAS

Apologies if I have mis-understood you.

Personally, I was taught to use BODMAS, which is why I recognised this.
B - Brackets
O - pOwers
D - Divide
M - Multiply
S - Subtraction

11. Originally Posted by kwah
I'm assuming you're using MDAS to represent the order in which you must process an equation?
M - Multiply
D - Divide
S - Subtraction

It should, in fact, be Divide first and then Multiply; ie, DMAS

Apologies if I have mis-understood you.

Personally, I was taught to use BODMAS, which is why I recognised this.
B - Brackets
O - pOwers
D - Divide
M - Multiply
S - Subtraction
Nice mnemonic but the precedence of multiply/divide and addition/subtraction
pairs is the same in the usual conventions.

RonL

12. Originally Posted by CaptainBlack
Nice mnemonic but the precedence of multiply/divide and addition/subtraction
pairs is the same in the usual conventions.

RonL
Yeah, I accept that its only a very trivial point, but thought I should point it out in case lancemaria (or anybody, as a matter of fact) have been learning it incorrectly.
I know from experience that simple trivialities, such as this, can be very irritating when you are unable to find out where you have gone wrong.

13. ## Order of Operations

I was taught PEMDAS

Parentheses
Exponents
Multiply (left to right)
Divide (left to right)
Add (left to right)
Subtract (left to right)

I remember it by "Please Exuse My Dear Aunt Sally"

14. i hope that the 'dot' means '.' ....

15. i guess she means multiply by writing it as "dot"

O_o'

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