Respuesta :

Answer: 2a+3b=12

               b=(12-2a)/3

5a-b=13

b= -13+5a

Step-by-step explanation:

1) 2a+3b=12

-2a        -2a

3b=12-2a

/3         /3

b= (12-2a)/3

2) 5a-b=13

   -5a     -5a

-b=13-5a    

*-1   *-1   -b= 13(-1)-5a(-1) *you'd multiply by -1 to cancel out the negative on b*

b= -13+5a