Question

Putin ajutor va rog!

Sa se rezolve ecuatia: 2x+4x+6x+...+100x+102= x+3x+5x+...+101x

si Sa se afle X din ecuatia (2000-x)-(1985+x)=3

Answer 1

1) x(2 + 4 + 6 +...+100) + 102 = (1+3+5+...+ 100 +101)x =>
2·x·(1+2+...+50) + 102 = x·50² + 101x
=> 2·x·50·51/2 + 102 = 2500x + 101 x
=> 2550x + 102 = 2601x
=> 51x =102
=> x = 102/51 = 2; 

2) (2000-x)-(1985+x)=3
=> 2000 - x -1985 -x = 3
=> 15 - 2x = 3
=>12= 2x
=> x=6