1. 234-145=89
2. 11101=1*[tex]10^{4}[/tex]+1*[tex]10^{3}[/tex]+1*[tex]10^{2}[/tex]+0*[tex]10^{1}[/tex]+1*[tex]10^{0}[/tex]
3. 2*13=26, 2+13=15
4. multiplii lui 7 cuprinsi intre:20 si 63=21,28,35,42,49 si 53, 6 numere in total
5. a*c-b*c=? c=4, a-b=11
c*(a-b)=4*11=44
6. 25 este patratul perfect lui 5
7. A=10^2017+2x10^2016+1
A=10...0(de2017ori)+2*10...0(de2016ori)+1
A=10...0(de2017ori)+20...0(de2016ori)+1
A=120...0(de2016ori)+1
A=120...01( 0 de 2015 ori)
Suma cifrelor lui A=SA
SA=1+2+0+0+...+0+1
SA=1+2+0*2015+1
SA=3+0+1
SA=4
8. 44x+4x4+x44=1221
400+40+X+400+10X+4+100X+40+4
888+111x=1221
111x=1221-888
111x=333
x=333:111
x=3
9.
[tex]2^{7}*3^{8}+2^{9}* 3^{7}+2^{7}*3^{8} \\a=2^{7} *3^{7} (3+2^{2} +3)\\a=(2*3)^{7} *(6+4)\\a=6^{7} *10[/tex]
a divizibil cu 5
10. x:y=3rest19
x=3y+19
a) 2*(3y+19)-6y+3=
6y+38-6y+3=41
b) 3y+19+y>95
4y>95-19
4y>76
y>76:4
y>19
4*19=76, nu este mai m are decat 95, relatia este falsa
c) 3y+19-y<61
2y+19<19
2y<0
y<0
0<61, relatia este adevarata
11. B-baieti
F-fete
B=2F
B-4=3(F-4)
2F-4=3F-12
3F-2F=12-4
F=8
B=16
