Question

Use identity and find the product of (51)$51 x^{2} -49 x^{2}$

Answer 1

51 x 51 = (50 + 1)²

= 2500 + 1 + 100

= 2601 

51x² - 49 x² = 2x²

Answer 2

$51 x^{2}$ = (50+1)²
        =2500+100+1
        =2601
$49 x^{2}$=(50-1)²
       =2500-100+1
       =2501-100
       =2401

$51x^{2} -49 x^{2}$=(2601-2401)
               =200

⇒$51 x^{2} -49 x^{2} =2 x^{2}$