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According to question,
….(i)
(a – b) = 18
ab = 144 ……(ii)
We know,
And,
(a + b) = 30
Also,
Now,
= (30)(18) = 540
Hence, option B is the correct answer.
Here, a = (326+222) & b = (326 – 222)
So,
=
Divisibility of 8 - A number is divisible by 8 if the last three digits of the number are divisible by 8.
Divisibility of 3 - A number is divisible by 3 if the sum of the digits of the number is divisible by 3.
Take, 52668 -
Last three digit 668 is not divisible by 8.
Take 49512 -
Last three digit 512 is divisible by 8
And the sum of digits (4+9+5+1+2=21) is also divisible by 3.
Hence, 49512 is divisible by 24.
Add 2 on both sides
Hence, option D is the correct answer.
Squaring on both sides
Now, cubing on both sides
⇒ (x + 1/x)2 – 2 = 7
⇒ (x + 1/x)2 = 9
⇒ (x + 1/x) = 3
∴ x3 + 1/x3 = (3)3 – 3(3)
= 27 – 9 = 18
x = 7 and y = 2
∴ [x3 – y3]/[x2 – y2] – [3xy]/[x + y]
= [(x-y)(x2+y2+xy)]/[(x-y)(x+y)] – [3xy]/[x+y]
= [x2+y2+xy]/[x+y] – [3xy]/[x+y]
= [x2+y2-2xy]/[x+y]
= [x-y]2/[x+y]
= [7-2]2/[7+2]
= 25/9
Hence, option C is the correct answer.
Now, a + 1/a = P2
∴ a2 + 1/a2 = (P2)2 – 2
= P4 – 2
Correct (-)
Wrong (-)
Skipped (-)