diketahui,a=-15,b=27,dan a-b+c=-21.tentukan nilai c

-15+27+c=-21
c = -21-27+15 =-33

Dik:
a = -15
b = 27
a - b + c = -21

Dit:
c = .................. ?

Jwb:
a - b + c = -21
-15 - 27 + c = -21
-42 + c = -21
c = -21 + 42
c = 21