Odpowiedź:
2(4x+5y-8)+5(3x-2y+8)= 8x+10y-16+15x-10y+40=
= 23x+24
(5a-9b+8)-(-3a-19b+10)= 5a-9b+8+3a+19b-10=
=8a+10b-2
-(4a+9m-12)-8(-3a+4m-12)= -4a-9m+12+24a-32m+96=
=20a-41m+108
(-12n+8k-20):4-(-3n+12k-9)= -3n+2k-5-3n-12k+9=
=-6n-10k+4
4d-3(-2b+7m-12)+(20d-12b+6m):(-2)+14=
=4d+6b-21m+36-10d+6b-3m+14= -6d+12b-24m+50