Question

Without actual finding the numbers find the value of
1) $100 x^{2} -99 x^{2}$
2)$26 x^{2} -25 x^{2}$

Answer 1

1.
100² - 99²
applying the formula: a² - b² = (a+b)(a-b)
= (100+99)(100-99)
= 199 × 1
= 199

2. 
26² - 25²
applying the formula: a² - b² = (a+b)(a-b)
= (26+25)(26-25)
= 51 × 1
= 51

Answer 2

100²-99²

apling the formula : a²-b²=(a+b)(a-b)

(100+99)(100-99)

199×1

=199