Question

Simplifique as expressões:
a) (3y+2)² - (y+3)²
b) 7x-(3x+3)²

Answer 1

Resposta:

a)

$(3y+2)^2-(y+3)^2\\9y^2+12y+4-(y^2+6y+9)\\9y^2+12y+4-y^2-6y-9\\8y^2+6y-5$

b)

$7x-(3x+3)^2\\7x-(9x^2+18x+9)\\7x-9x^2-18x-9\\-9x^2-11x-9$

Explicação passo-a-passo:

a)

$(3y+2)^2-(y+3)^2\\9y^2+12y+4-(y^2+6y+9)\\9y^2+12y+4-y^2-6y-9\\8y^2+6y-5$

b)

$7x-(3x+3)^2\\7x-(9x^2+18x+9)\\7x-9x^2-18x-9\\-9x^2-11x-9$

Answer 2

a)

$\mathsf{(3y + 2)^2 - ((y + 3)^2 = 9y^2 + 12y + 4-(y^2 + 6y+9) =\boxed{\mathsf{ 8y^2 + 6y- 5}}}$

b)

$\mathsf{7x - (3x+3)^2 = 7x - (9x^2 + 18x + 9) =\boxed{ \mathsf{-9x^2-11x-9}}}$