Respuesta :

Step-by-step explanation:

In the second step while opening the bracket, instead of 'a', there should be - 4a.

Answer:

From Step 2 every step is wrong

Step-by-step explanation:

Ste p 1 : 3a - 5b = 12 - 4(b + a)

Step 2 : 3a - 5b = 12 - 4b - 4a      [ Last term instead - 4a she\he wrote + a ]

Step 3 : 7a  - 5b = 12 - 4b

Step 4 : 7a = 12 + b

[tex]Step 5 : a = \frac{12 + b}{7}[/tex]