WILL GIVE BRAINLIEST
Insert negative signs, and addition and subtraction symbols to make each sentence true. Example: 1 = 1 +(-2)+(-3)+4+(-5)+6
a. 7= 1?2?3?4?5?6 b. 3= 1?2?3?4?5?6
c. -1=1?2?3?4?5?6 d. -11=1?2?3?4?5?6