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

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

you want to find the value of B and M right ??

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

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

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

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

the sum of (1) and (20

$\displaystyle 26B=19500$

$\displaystyle B=750$

sub B value in (b)

$\displaystyle 3M+5(750)=4800$

$\displaystyle M=350$

the difference between them $\displaystyle 750-350=400$

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