Question

Determinati numerele naturale de forma ab stiind ca 3×ab+3×ba=198

Answer 1

3*ab+3*ba=198
3*10a+b+3*10b+a=198
3*(11a+11b)=198
11a+11b=198 :3=66
11(a+b)=66
a+b=66:11=6
a=1  b=5
a=2  b=4
a=3  b=3
a=4  b=2
a=5  b=1
ab∈{15 ; 24 ; 33 ; 42 ; 51}

Answer 2

3*ab+3*ba=198
3*(ab+ba)=198
ab+ba=198:3
ab+ba=66
10a+b+10b+a=66
11a+11b=66
11*(a+b)=66
a+b=66:11
a+b=6
ab∈{15,24,33,42,51}