Помогите решить 1/3+(-2/9)+4/27+(-8/81)= 2/3+(-4/9)+8/27+(-16/81)=...

Question

Помогите решить 1/3+(-2/9)+4/27+(-8/81)= 2/3+(-4/9)+8/27+(-16/81)=
3/4+(-5/8)+7/16+(-9/32)=

5/4+(-7/8)+9/16+(-11/32)=

Answer 1

1) ...=(27/81)-(18/81)+(12/81)-(8/81) = (27-18+12-8)/81 = 13/81

2) ...=54/81-36/81+24/81-16/81 = (54-36+24-16)/81 = 26/81

3) ...=24/32-20/32+14/32-9/32 = (24-20+14-9)/32 = 9/32 = 0.28125

4) ...=40/32-28/32+18/32-11/32 = (40-28+18-11)/32 = 19/32 = 0.59375