Question

va rog mult ex 22 cine ma poate ajuta

Answer 1

$x=1+2+3+...+20=10*21=210\\ \\ y=2(1+2+3...+20)= 2x=420\\ \\ z=3(1+2+3+...+20)=3x=630\\ \\ x+y+z=6x=1260\\ \\ \\ Am~folosit~formula~lui~Gauss:~1+2+3+...+n=\frac{n(n+1)}{2}.$

Answer 2

A) X= 20×21 ÷ 2
X= 420 ÷ 2
X=210
Y=2+4+6+...+40 |÷2
Y=1+2+3+...+20
Y=420
Z=3+6+9+...+60 |÷3
Z=1+2+3+...+20
Z=420 ×3 ÷ 2
Z=1260 ÷ 2
Z= 630
B)
210+420+630=1260