Question

Vamos calcular:

a) (x + 7) . (x + 5)
b) (y – 6) . (y + 5)
c) (2a + b) . (a – 2b)
d) (-28x + 8x²) : (4x²)
e) (a²b – ab²) : (ab)
f) (35a²x³ - 20 a³x²) : (5a²x)

Answer 1

Propriedade distributiva:

a)
(x + 7) . (x - 7) = x² - 49x + 7x - 49 = x² - 42x - 49

b)
(y - 6) . (y + 5) = y² + 5y - 6y - 30 = y² - y - 30

c)
(2a + b) . (a - 2b) = 2a² - 4ab + ab - 2b² = 2a² - 2b²- 3ab

d) (- 28x + 8x²) : (4x²) =

$\frac{-28x+8 x^{2} }{y} . \frac{1}{4 x^{2} } =$

4x² . (- 28x + 8x²) = - 112x³ + 32x⁴ = 32x⁴ - 112x³

e)
(a²b - ab²) : (ab) =

mmc = ab

$\frac{ a^{2}b-a b^{2} }{ab}$

f)
(35a²x³ - 20a³x²):5a²x =

$\frac{35 a^{2} x^{3} -20 a^{3} x^{2} }{5 a^{2}x }$

Answer 2

a) x^2 + 5x + 7x + 35=>x^2 + 12x + 35
b)y^2 +5y -6y - 30=>y^2 - y -30
c)2a^2 - 4ab + ab -2 b^2=>2a^2-3ab-2b^2
d) -28x + 8x^2 /4x^2=>4.(-7+2x)/4x^2=> -7+2x/x
e) a^2 - ab^2/ab=>ab. (a-b)/ab=>a-b
f)35a^2 x^3 - 20a^3 x^2/5ax^2 =>5ax^2 (7x^2 - 4ax)/ 5a^2 x =>7x^2 - 4ax