Question

Desfaceti parantezele
Ex 13

Answer 1

Răspuns:

Explicație pas cu pas:

a)

(2x - 3y)(5x + 7y -1) = 10x^2 + 14xy - 2x - 15xy -21y^2 + 3y = 10x^2 - 21y^2 - xy - 2x + 3y

b)

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

c)

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

d)

(x^2 - y^2)(x + y) = x^3 + yx^2 - xy^2 - y^3

e)

(a + 2)(a^2 - 2a + 4) = a^3 - 2a^2 + 4a + 2a^2 - 4a + 8 = a^3 + 8

f)

(x + 1)(x^2 - x + 1) = x^3 - x^2 + x + x^2 - x + 1 = x^3 + 1