Question

a x 3 + b x 3 = 165
( a x 3 - b x 3 )x 3 = 45
Aflati a si b .

Answer 1

a x 3 + b x 3 = 165 
3( a+ b ) = 165 
a +b = 165 : 3 = 55


( a x 3 - b x 3 )x 3 = 45 
a x 3 - b x 3 = 45 : 3 = 15 
3( a - b ) = 15 
a - b = 15 : 3 = 5 
a = 5 + b 

5 + b + b = 55 
5 + 2b = 55 
2b = 55 - 5 = 50 
b = 50 : 2 
b = 25 
a = 5 + 25 = 30 

Answer 2

3(a + b) = 165         | : 3
a + b = 55
3(a - b) : 3 = 45       | : 3
a - b = 15
a + b = 55
a - b = 15
le adunam
2a = 60
a = 60 : 2
a = 30
b = 55 - 30
b = 25