a) \(\left(x-2891\right):3=40688\)
= \(\left(x-2891\right)=40688.3=122064\)
= \(\left(x-2891\right)=122064+2891=124955\)
b) \(\left(x+2891\right):3=10512\)
= \(\left(x+2891\right)=10512.3=31536\)
= \(\left(x+2891\right)=31536-2891=28645\)
a, ( x - 2891 ) : 3 = 40688
( x - 2891 ) = 40688 x 3
x - 2891 = 122064
=> x = 122064 + 2891
=>x = 124955
b, ( x + 2891 ) : 3 = 10512
( x + 2891 ) = 10512 x 3
x + 2891 = 31536
=> x = 31536 - 2891
=> x = 28645