Question

Calculati x+y si y+(-x) in urmatoarele cazuri :
a) x=(-72)+I-28I+(-87) si y=I59I+(-98)+(-79);
b) x=I92I+(-165)+(-83) si y=(-75)+I-29I+127.

Answer 1

a)
 x=(-72)+(-28)+(-87) = -72 - 28 -87 =  - 187 

 y= (59)+(-98)+(-79) = 59 - 98 - 79 = -118 

x + y = -187 + (- 118) = - 187 - 118 = - 305 
y + (-x ) = - 118 + ( - (-187)) = -118 + 187 = 69

b)
x = (92)+(-165)+(-83) = 92 - 165 - 83 = -156 
 
y =(-75)+(-29) +127 = - 75  - 29 + 127= 23 

x + y = - 156 + 23 = -133
y + ( - x) = 23 + (-(-156))  = 23 + 156 = 179 

Answer 2

a)x=(-72)+I-28I+(-87)=-72+28-87=-131
x=-131
y=I59I+(-98)+(-79)=59-98-79=-118
y=-118
x+y=-131+(-118)=-249
y+(-x)=-118+(-(-131))=-118+131=13
b)x=l92I+(-165)+(-83)=92-165-83=-156
y=(-75)+I-29I+127=-75+29-127=-173
x+y=-156+(-173)=-329
y+(-x)=-173+(-(-156))=-17