Question

решите ​

Answer 1

$(b + 3)( {b}^{2} - b - 7) = b( {b}^{2} - b - 7) + 3( {b}^{2} - b - 7) = b {}^{3} - {b}^{2} - 7b + 3 {b}^{2} - 3b - 21 = b {}^{3} + 2 {b}^{2} - 10b - 21$