# Math Help - Algebra

1. ## Algebra

This came from one of the questions from my math test...

7M+3B=4700
3M+5B=4800

difference between B+M = 400

Pls help urgently. Thanks.

Anna

P.S sorry, I just realised I posted in the wrong thread... could any of the mods please help with this?

2. Originally Posted by AnnaRydell
This came from one of the questions from my math test...

7M+3B=4700
3M+5B=4800

difference between B+M = 400 the difference or the sum

Pls help urgently. Thanks.

Anna

P.S sorry, I just realised I posted in the wrong thread... could any of the mods please help with this?
you want to find the value of B and M right ??

$7M+3B=4700$.....(a) multiply with -3

$3M+5B=4800$.....(b) multiply with 7

$-21M+-9B=-14100$ ......(1)

$21M+35B = 33600$......(2)

the sum of (1) and (20

$26B=19500$

$B=750$

sub B value in (b)

$3M+5(750)=4800$

$M=350$

the difference between them $750-350=400$

3. To state clearly...B-M = 400

The question asked for B but its okay I know now yeah... Thanks Amer!

Anna

4. Originally Posted by AnnaRydell
difference between B+M = 400
This is not required in order to solve.
Hope you realise that.

5. Originally Posted by AnnaRydell
This came from one of the questions from my math test...

7M+3B=4700
3M+5B=4800

difference between B+M = 400

Pls help urgently. Thanks.

Anna

P.S sorry, I just realised I posted in the wrong thread... could any of the mods please help with this?
7m+3b=4700
If you multiply 4700 with 5 (take the answer as y), you will get the answer for 35m+15b.

3m+5b=4800
If you multiply 4800 with 3 (take answer as x), you will get the answer for 9m+15b.

Then, you subtract x by y (take answer as a).

Then, divide a by 32 to find m.