Question

Помогите решить
(3a-c)^2
(y-5)(y+5)
(4в+5c)(4в-5c)

Answer 1

$(3a - c) {}^{2} = 9a {}^{2} - 6ac + c { }^{2} \ (y - 5)(y + 5) = y {}^{2} - 25 \ (4b + 5c)(4b - 5c) = 16b {}^{2} - 20bc + 20bc - 25c {}^{2} = 16b {}^{2} - 25c {}^{2}$