Question

Zad.1-Wykonaj działania:

a) (m+n)(m-2) + (m-n)(m+1)
b) (3x-2)(3x-2y+1)-4x(2x-3y+1)
c) 3(m+1)(n-2)+2(n+1)(m-2)
d) x(x+1)(x+2)-x(x-1)(x-2)


Poproszę obliczenia

Answer 1

A) (m+n)(m-2) + (m-n)(m+1)=
m2-2m+nm-2n+m2-m-nm-n=
2m2+m-3n


b) (3x-2)(3x-2y+1)-4x(2x-3y+1)=
9x2+4y+1-8x2+12xy-4x=
x2+4y+1+12xy-4x



c) 3(m+1)(n-2)+2(n+1)(m-2)=
3(mn-2m+n-2)+2(nm-2n+m-2)=
3mn-6mn+3n-6+2nm-4n+2m-4=
-mn-n-10+2m




d) x(x+1)(x+2)-x(x-1)(x-2)=
x(x2+2x+x+2)-x(x2-2x-x+2)=
x3+2x2+x2+2x-(x3-2x2-x2+2x)=
x3+2x2+x2+2x-x3+2x2+x2-2x=
4x2+4x2=
8x2


Uff .. ;p