Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 month 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
1 month ago

5a + 3b - c

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

= 25

• 1 month ago

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

25+9-9=25

25=25

Math seems to be working today.

• 1 month 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.

• 1 month ago

sum of

9+(-9)=0

you are not completing the process.

• 1 month ago

34 - 9 = 25, not 23

• 1 month ago

5a + 3b - c = 25

5(5) + 3(3) - 9

25 + 9 - 9

= 25 prove.

• Bill
Lv 6
1 month ago

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

• 1 month 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

• 1 month 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

;))

• 1 month ago

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