785x3678y

Devisible by 72 -> 2^3•3^2

-> y=4

7+8+5+x+3+6+7+8+y=44+x+y

44+x+4=48+x devisible by 9

x=6

7x-5y=42-20=22

a^3+b^3-c^3+3abc=

a+b=c

(a+b)^3-3ab(a+b)-c^3+3abc=
c^3-3abc-c^3+3abc=0

B

763x4y2

7+6+3+x+4+y+2=22+x+y

x+y=2,5,8

x+y=2 -> x=y=1

x+y=5 -> x=1, y=4; x=2, y=3

x+y=8 -> x=1, y=7; x=2, y=6; x=3, y=5; x=4, y=4

7

x=3+2sqrt(2)
1/x=3-2sqrt2

x+1/x=6

x^2+1/x^2=(x+1/x)^2-2=36-2=34

a^2+1/a^2=(a-1/a)^2+2=38
a-1/a=6

a^3-1/a^3=(a-1/a)^3+3(a-1/a)
a^3-1/a^3=234

New Doc 20 - Page 1

X ka vhalue batao

Solution

1001+n^=a^2
A^2-n^2=1001
(a+n)(a-n)=1*13*11*7
a-n=1*13
a+n=11*7=77
N=64/2=32
Possible solution (45,32)(51,40)
(75,68)(501,500)
Sum 500+68+40+32=640