Question

$(x + y)(x + b) = x {}^{2} + (y + b)x + yb$
помогите решить даю 20 балов​

Answer 1

(x+y)(x+b) = x² + (y+b)x + yb

x² + bx + xy + by = x² + xy + bx + by

x² - x² + bx - bx + xy - xy + by - by = 0

0 = 0