Question

Va rog ajutati-ma cu 2-3 ex si dau coroana si multumiri si puncte!~~

Answer 1

G.2145
a , b i.p. 0,(3) si 0,(6) => a*0,(3) = b*0,(6)=k
0,(3)=3/9=1/3
0,(6)= 6/9=2/3
=> a*1/3 = b*2/3=k
a*1/3=k => a= 3k
b*2/3=k => b= 3k/2
2*b+3*a=24 => 3k+9k=24 => 12k=24  =>k=2
=> a=6 si b= 3
G.2156.
12n!=(n+2)! => 12 n!= n! (n+1)(n+2) => 12= (n+1)(n+2) => 12=n²+3n+2 =>
n²+3n-10=0
Δ=9-4(-10)=49
n1/2 = (-3+_7)/2 => n1=-5 si n2= 2 cum n∈ N => n=2