Răspuns:
Explicație pas cu pas:
a) (a-2)²+(a-1)² = (a²-4a+4)+(a²-2a+1) = 2a²-6a+5
b) (x-3)²-(2-x)² = (x-3-2+x)(x-3+2-x) = (2x-5)(-1) = 5-2x
Am folosit formula : a²-b² = (a-b)(a+b)
c) (2-x)²-(1-3x)² = (2-x-1+3x)(2-x+1-3x) = (1+2x)(3-4x) =
= 3-4x+6x-8x² = -8x²+2x+3
d) (5-x)²+x²-(1-2x)²-2x² = 25-10x+x²+x²-1+4x-4x²-2x² =
= -4x²-6x+24
e) (a-2b)²-4a²+(2a-b)²-4b² = a²-4ab+4b²-4a²+4a²-4ab+b²-4b²=
= a²-8ab+b²
#copaceibrainly
