Question

1.Aflati numarul a stiind ca : [5×(5×5+5:5)-a]:10=3


2.Aflati numerele naturale X si Y astfel incat :
{3×[12+(6+2×X+3×Y) :5]-9}:6+15=21

Answer 1

1.[5×(25+1)-a]=30
5×26-a=30
a=130-30
a=100
2.{3×[12+(6+2x+3y):5]-9}=(21-15)×6
3×[12+(6+2x+3y):5=36+9
3×[12+(6+2x+3y)=45×5
12+(6+2x+3y)=45:3×5
6+2x+3y=75-12
2x+3y=63-6
2x+3y=57
pr x=9
2×9+3y=57
3y=39
y=13
x=9
pt x=6
12+3y=57
3y=57-12
3y=45
y=15
ptx=3
6+3y==57
y=51:3
y=17