Can you express the product 15 × 16 as sum or difference of integers? Yes, here are 4 ways to compute 15 ×16 = +240 . (i) 15 ×16 = (10 + 5)× (10 + 6) = 100 + 60 + 50 + 30 = 240 (ii) 15 ×16 = (20 − 5)× (10 + 6) = 200 +120 + (−50)+ (−20) = 240 (iii) 15 ×16 = (10 + 5)× (20 − 4) = 200 + (−40)+100 + (−20) = 240 (iv) 15 ×16 = (20 − 5)× (20 − 4) = 400 + (−80)+ (−100)+ 20 = 240 From the above pattern one can determine the product of two positive integers, two negative integers, one positive integer with one negative integer.
Answers
Given:
15 ×16 = +240 .
To find:
Can you express the product 15 × 16 as sum or difference of integers? From the above pattern one can determine the product of two positive integers, two negative integers, one positive integer with one negative integer.
Solution:
From given, we have,
15 ×16 = +240 .
(i)The product of two positive integers
(i) 15 ×16 = (10 + 5)× (10 + 6) = 100 + 60 + 50 + 30 = 240
(ii) The product of one negative integer with one positive integer.
(ii) 15 ×16 = (20 − 5)× (10 + 6) = 200 +120 + (−50)+ (−20) = 240
(iii) The product of one positive integer with one negative integer.
(iii) 15 ×16 = (10 + 5)× (20 − 4) = 200 + (−40)+100 + (−20) = 240
(iv) The product of two negative integers
(iv) 15 ×16 = (20 − 5)× (20 − 4) = 400 + (−80)+ (−100)+ 20 = 240