Question

Cine o rezolva dau coroana​

Answer 1

Răspuns:

a=(2+4+6+..+100)-50

(2+4+6+..+100)=(1+2+3+..+50)=50•51/2=1275

1275-50=1225

==> a=1225

a²=1225

a=√1225

==> a=35

Answer 2

Răspuns:

a=(2+4+6+...+100)-50

2+4+6+...+100= 2(1+2+3+...+50)=

2×50(50+1)/2= 50(50+1)=

50×51=2.550

a= 2.550-50= 2.500

$\sqrt{a} = \sqrt{2500} = 50$