Anonymous
Anonymous asked in Science & MathematicsMathematics · 5 months ago

# 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.

Relevance
• sepia
Lv 7
5 months ago

5a + 3b - c

= 25 + 9 - 9 (if a = 5, b = 3 and c = 9)

= 25

• 5 months ago

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

25+9-9=25

25=25

Math seems to be working today.

• 5 months 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.

• 5 months ago

sum of

9+(-9)=0

you are not completing the process.

• 5 months ago

34 - 9 = 25, not 23

• 5 months ago

5a + 3b - c = 25

5(5) + 3(3) - 9

25 + 9 - 9

= 25 prove.

• Bill
Lv 6
5 months ago

5X5=25,3X3= 9 so 5a +3B =25 +9=  34-9 =25

• 5 months 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

• 5 months 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

;))

• 5 months ago

How are you getting 23 from 34 - 9?  34 - 9 = 25