# Math problem?

If a=5, b=3 and c=9

How is

5a + 3b - c = 25

I get 23 using the rules of bidmas as follows:

(5x5) + (3x3) - 9

25 + 9 - 9

34 - 9

Am I doing it wrong using bidmas to solve?

Any help to explain why I should subtract prior to addition, when it's that order, will be greatly appreciated.

### 15 Answers

- PuzzlingLv 74 weeks ago
Are you doing the last subtraction correctly?

34

-9

----

25

I don't see where you get 23

One other reminder about BIDMAS/BODMAS/PEMDAS or whatever mnemonic you are using.

Multiplication and Division have equal precedence so when you are doing those operations, go left to right.

Similarly, Addition and Subtraction have equal precedence, so when you do those, also go left to right.

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- KrishnamurthyLv 74 weeks ago
If a = 5, b = 3 and c = 9

5a + 3b - c = 25

How?

(5×5) + (3×3) - 9

= 25 + 9 - 9

= 34 - 9

= 25

- 4 weeks ago
Technically, when adding and subtracting, you do so in order as they appear from left to right. This means that your steps are correct, meaning that it should look like this:

5(5)+3(3)-9=25

25+9-9=25

34-9=25

25=25

left side=right side

;))