Question

zad.1 Oblicz wartości liczbowe wyrażeń dla podanych wartości zmiennych.

a). x(3xy -y)- y(x²-xy +x) dla x= -1 , y= ¹/₅

zad.2

Wyłącz wspólny czynnik przed nawias.

a). k²l - kl²

b). x² - 2x² + x

c). 3ab² - 2a²b- ab

d). ¹/₂ ac²- ¹/₄ a² + ¹/₂ a

Answer 1

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Zad.1

a)

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

2x^2 + xy^2= 2*(-1) * 1/25= 2- 1/25 = 1 24/25

 

Zad. 2

a) k^2 - kl^2 = kl (k-l)

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

c) 3ab^2 - 2a^2b- ab = ab (3b- 2a-1)

d) 1/2 ac^2 - 1/4 a^2 + 1/2 a^2= 1/2a (c^2 - 1/2 a +1)

 

                                                                                                          

 

Answer 2

zad1 

x(3xy - y)-y(x ²-xy+x)=

3x²y-xy -x²y+ xy²-xy=

2x²y-x²y+x²y²=

2*(-1)²* ⅕-(-1)²*⅕-1*(⅕)²=

2*⅕-⅕-¹/₂₅=²/₅ -¹/₅ -¹/₂₅= ¹/₅ - ¹/₂₅ = ⁵/₂₅ - ¹/₂₅ = ⁴/₂₅