Question

The equation is as below:-​

Answer 1

Answer:$-a^3b + 13a^2b^2 - 13ab + 5$

Step-by-step explanation:

$( a^3b + 6a^2b^2 - 7ab + 4) - (-7a^2b^2 + 2a^3b + 6ab -1)\\= a^3b + 6a^2b^2 - 7ab + 4 + 7a^2b^2 - 2a^3b - 6ab + 1\\= a^3b - 2a^3b + 6a^2b^2 + 7a^2b^2 -7ab - 6ab + 4 + 1\\= (1-2)a^3b + (6+7)a^2b^2 - (7+6)ab + (4+1)\\=(-1)a^3b + (13)a^2b^2 - (13)ab + (5)\\= -a^3b + 13a^2b^2 - 13ab + 5$