Question

as vrea aici o idee sau o rezolvare.Ofer corona

Answer 1

E(x) =4x²+12x+9

-x² +4

-3x²+6x -3=

=18x+10

E(1) +E(2)+....+E(25)=18(1+2+...+25) +10*25=18*25*26/2+250=5850+250=6100

problema 5

n=4a+3

n=6b+5

n=9c+8

n+1=4a+3+1=4a+4=4(a+1)=4d

n+1=6b+5+1=5b+5=6(b+1)=6e

n+1=9c+8+1=9c+9=9(c+1)=9f

n+1 divizibil cu 4;5;9⇒n+1 divizibil cu [4,6,9]=4*9=36

n+1=36k

n=36k-1

100<n<250

convin 3*36-1=107

4*36-1=143

5*36-1=179

6*36-1=215