1.

Use Euclids division lemma to show that the cube of any positive integer is of the form 9m,9m+1or9m+8 ​

Answer»

JAY SHREE KRISHNA

YOURANSWERASFOLLOW

cube of any positive integer:- 9m, 9m+1, 9m+8

Let a be any positive integer and b=3

0<equal to r < b

0<equal to r < 3

r= 0, 1, 2

a = 3q + r...............(1)

If r= 0 in equation (1)

a=3q+0

a=3q

cube both side

a³= 27q³

a³= 9(3q³)

a³= 9m [m= (3q³)]

If r=1 in equation (1)

a= 3q+1

cube both side

a³= (3q+1)³

= 27q³+1+3(3q)²+(1)+3(3q)(1)²

=27q³+27q²+9q+1

|___________|

=9(3q³+3q²+q)+1

a³= 9m+1 [m= (3q³+3q²+q)]

If r=2 in equation (1)

a=3q+2

cube both side

a³= (3q+2)³

=27q³+8+3+(27q²)+2)+3(27q)(4)

=27q³+54q²+36q+8

=9(3q³+6q²+4q)+8

a³=9n+8 [m= 3q³+6q²+4q)]

PLS MARK AS BRAINLIST FOR THIS BIG ANSWET

JAY SHREE KRISHNA



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