2ab= a 2 + b 2 - a 2 - b 2

29-9=20

=>ab=10

x = y  <=> 1 - q =  2q  + 1  <=> 3q  = 0 <=> q = 0.

Given Expression =  18800 470 ÷ 20 =  40 ÷ 20 = 2

50.003% of 99.8 ÷ 49.988 = ?

? ~= (50 x 100/100)/50

? ~= (50 x 100)/(100 x 50)

? ~= 1

a b × b c = 4 5 × 15 16 = 3 4 = 16 - 9 16 + 9

= 7 25

Using BODMAS Rule,

First solve division, mutiplication and Addition

So here 10/2 = 5

Then 2 x 5 =  10

Now, 5 + 10 = 15.

Hence, 5 + 2 x 10/2 = 15.

Given,

 5sinx + 12cosx ? -r 

? 13 5 13 sin x + 12 13 cos x ? - rcosx) ? -r 

5 13= cosA => sinA = 12 13

=> 13(sinx cosA + sinA cosx) ? -r

=> 13(sin(x + A)) ? -r

we know that , -1 ? sin (angle) ? 1

=> 13sin (x + A) ? -13 ? r m i n = 13 

Given a secret is told to 3 persons in 3 minutes.
And if the process continues with each person saying 3 other persons,
In 30 minutes => the rocess for 10 times because each person time is 3 minutes.
Required number of persons =  3 + 3 2 + 3 3 + . . . . + 3 9 + 3 10

Now it forms a geometric progression,

Sum to n terms is S = a r n - 1 r - 1

Here a = 3, r = 3

 
=> 59048 x 3 /2

= 88572.

Half of the cloth = 37.5/2
From 1 meter he will make 8 pieces
=> in 37.5/2 ---- ?

37.5/2 x 8

= 150.

$$\begin{gathered} [ ( K - L ) 2 - K + L 2 ] 4 K = a b \\ K 2 + L 2 - 2 K L - K 2 + L 2 + 2 K L 4 K = a b \end{gathered}$$

=> - 4KL/4K = a/b

=> L = - a/b

=> bL = -a