Question

using suitable identity evaluate the following (12.5)²–(1.5)²​

Answer 1

Answer:

(12.5)² - (1.5)²

Using identity a² - b² = (a + b)(a - b)

(12.5)² - (1.5)² = (12.5 + 1.5)(12.5 - 1.5)

(12.5)² - (1.5)² = (14)(11)

(12.5)² - (1.5)² = 154

Answer 2

Answer:

The identity which can be used to solve this question is:-  a² -  b²

So,

a = 12.5

b = 7.5

The identity expands as = a + bAa - b

So,

Solution:-

=(12.5+7.5)×(12.5-7.5)

=20×5

Solution = 100.