Question

please answer all of them correctly

if you know anyone also
do it correctly and clearly
please

Answer 1

Ans9 - 0.54*0.54 - 0.46*0.46

-- 0.54² - 0.46²

-- We know a² - b² = (a+b) (a-b)

-- (0.54 + 0.46) ( 0.54 - 0.46)

-- 1 * 0.12

-- 0.12

Ans10- 185² - 15²

We know,

a² - b² = (a+b) (a-b)

(185+15) (185-15)

200 * 170

= 34000

Ans11 - 105 * 108

(100+5) (100+8)

We know,

(x+a) (x+b) = x² + (a+b)x + ab

100² + (5+8)100 + 5*8

10000 + 1300 + 40

= 11340