Question

Zapisz, w jak najprostszej postaci:

a) 2(x-y)(x+y)-(x-2y)²

b) (2a-b)²-2(a-b)(2a+b)

c) 5(s+3t)(3t-s)-(s+2t)²

d) (2+0,3)²+(z+0,2)(0,2-z)

Answer 1

a) 2x^2 - 2y^2 - x^2 - 4y^2 + 4xy = x^2 - 6y^2 + 4xy

 

b) 4a^2 + b^2 - 4ab -2 (2a^2 - ab - b^2 ) =  4a^2 + b^2 - 4ab - 4a^2 + 2ab + 2b^2 = 3b^2 - 2ab

 

c) 5(3ts - s^2 + 9t^2 - 3ts) - s^2 - 4t^2 - 4ts = -5s^2 + 35t^2 - s^2 -4t^2 -4ts = -6s^2 + 31t^2 -4ts

 

d) 5,29 + 0,2z -z^2 + 0,04 -0,2z = 5,29 -z^2 -0,2z