question_answer 15)

Find the sum: (a) (?7) + (?9) + 4 + 16 (b) (37) + (?2) + (?65) + (?8) TIPS Firstly, add the numbers having same sign and get new number. Now, add the numbers having opposite signs.

Answer:

(a) We have, \[(-7)+(-9)+4+16=-(7+9)+4+16\] \[[\because 20=16+4]\] \[=-16+20=-16+16+4\] \[=0+4=4\] \[[\because -16+16=0]\] (b) We have, \[(37)+(-2)+(-65)+(-8)=37-(2+65+8)\] \[=37-75=37-37-38\] \[[\because 75=37+38\Rightarrow -75-37-38]\] \[=0-38=-38\] \[[\because -37+37=0]\]