Question

Answer the this questions

Answer 1

Step-by-step explanation:

heya

we know that

every integer is of the form 5q+r where r =0,1,2,3,4

so case -1 a=5q

a²=25q²=5m

case-2 a=5q+1

a²=25q²+10q+1

a²=5m+1

similarly by rest of cases a²=5m+4,5m+4,5m+1

so it can only be in the form of 5m,5m+1,5m+4

it is not in the form of 5m+2 or 5m+3

hence verified

and for second question

put n=3q+r r=0,1,2

case -1 n=3q

so n+2=3q+2

n+4=3q+4

here only n is divisible by 3

similarly in each case only one is divisible

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