A1TUTORHUB

Q1. Find (a) 35 – (20)                                                              (b) 72 – (90) (c) (– 15) – (– 18)                                                      (d) (–20) – (13) (e) 23 – (– 12) (f) (–32) – (– 40) Solution/Explanation: To subtract two integers, we add the additive inverse of the integer that is being subtracted. So 2 -5 = 2+ (-5) as -5 is additive inverse of 5 Now we have already learned the addition of integers before a) 35 − (20) = 35+ (-20) Subtract 35 and 20 and put the sign of the bigger number 35, which is positive 15 b) 72 − (90) 72+(-90)   Subtract 72 and 90 and put the sign of the bigger number 90, which is negative -18 c) (− 15) − (− 18) = (-15) + (18) As additive inverse of -18 is 18 Subtract 15 and 18 and put the sign of the bigger number 18, which is negative 3 d) (− 20) − (13) = (-20) + (13) Subtract 20 and 13 and put the sign of the bigger number 20, which is negative -7 e) 23 − (− 12) =23+12 Adding the numbers 23 and 12= 35 f)

Using the number line write the integer which is : (a) 3 more than 5 (b) 5 more than –5 (c) 6 less than 2 (d) 3 less than –2 Solution/Explanation: More means moving right on the number line and less mean moving left on the Number line a) So answer is -5 Q2. Use number line and add the following integers :  (a) 9 + (– 6)                                           (b) 5 + (– 11)  (c) (– 1) + (– 7)                                     (d) (– 5) + 10  (e) (– 1) + (– 2) + (– 3)                         (f) (– 2) + 8 + (– 4) Solution/Explanation: Two important things to remember When we add positive integer, we move to the right When we add negative integer, we move to the right a)  9 + ( − 6 ) 9 + ( − 6 ) We start with number 9 and move to left six steps and we reach the number 3 b)  5 + ( − 11 ) 5 + ( − 11 ) We start with number 5 and move to left 11 steps and we reach the number -6 c)  ( − 1 ) + ( − 7 ) ( − 1 ) + ( − 7 ) We start with