1) [tex]1024= 2^{10} [/tex]
2)[tex]1,(3)= \frac{13-1}{9}= \frac{12}{9}= \frac{4}{3} [/tex]
3)complementare = impreuna au 90, daca unul are 25, celalalt are 90-25=65°
4)34x divizibile cu 3
Un număr natural este divizibil cu 3 dacă suma cifrelor sale se divide la 3
3+4+a=3⇒a=∈{2,5, 8} 342=3+4+2=9, 3+4+8=15, 348 , 3+4+5=12 345
342 , 345 si 348
⇒a=∈{2,5, 8}
5) se numesc coliniare
6)[tex] \frac{4}{5}= 0,8[/tex]
[tex] \frac{5}{6}=0,83333=0,8(3) [/tex]
deci [tex] \frac{5}{6}\ \textgreater \ \frac{4}{5} [/tex]
Partea a 2 a
2)
180 = 2² ×
3² ×5
120 =
2³ ×3 × 5
cmmdc(180,120)=2²×3×5=60
cmmmc(180,120)=2³× 3²× 5 = 360
3) 12=2²×3
20=2²×5
30=2×3×5
cmmmc=60
60+restul 3=63
numarul cautat este 63
verificare: 63:12=5 rest 3, 63:20=3 rest 3, 63:30=2 rest 3
4)28 = 2² ×7
45 = 3² ×5
c.m.m.d.c.=1
Cele 2 numere nu au nimic in comun, deci sunt prime intre ele.
5)4×[7²-7×(2⁴-3² - 3)]=
4×(49-7×4)=
4×(49-28)=
4×21=84
4×[7²-7×(2⁴-3² - 3)] = 84
III
a)∡BOC=180 - 36 = 144
b)∡COD = ∡DOB =72
c)AOD=36+72=108
∡AOD=3×∡AOB
