Question

i)If (x+2)( x-2)=x²-k, then what is the value of k?
ii)find 168²-167​

Answer 1

Answer:

i) (x+2) (x-2) = x^2 - k

or, (x)^2 - (2)^2 = x^2 - k

or, x^2 - 4 = x^2 - k

or, - 4 = - k

or, k = 4 (ans.)

ii) 168^2 - 167^2

= (168 + 167) (168 - 167)

= 335 × 1

= 335 (ans.)

Note :- 168^2 - 167 is wrong question & 168^2 - 167^2 is the right one.