Question

Expand the following expression:(a+ 3b)(a -b)​

Answer 1

(a+ 3b)(a -b)

= a^2 - ab + 3ab - 3 b^2

= a^2 + 2ab - 3b^2

Hope this will help

Answer 2

(a+ 3b)(a -b)

= a²-ab +3ab -3b²

» a² +2ab -3b²