Question

(a+b)•(b+c)=?
(3x+bx+c)•(b+c)=?

Answer 1

$(a + b)(b + c) = ab + ac + {b}^{2} + bc$

$(3x + bx + c)(b + c) = \\ 3bx + {b}^{2} x + bc + 3xc + bxc + {c}^{2}$