1.5/12+7/10=(5*5+7*6)/60=(25+42)/60=67/60
2.1,3+2,5=3,8(5)
3.2:(2/3)²+11/5:11/10=
=2 *(3/2)²+11/5 *10/11=
=2 *9/4+2=
=9/2+2=(9+4)/2=13/2
4.
-3,45 =-345/100=-69/20
-3,455=3455/1000=691/200
5.(-1/2)⁴(1/2)³(-1/2)⁻⁶=
=(1/2)⁴ ×(1/2)³(2)⁶=
=(1/2)⁷(2)⁶= 1/2
6
n-3=5
n=5+3=8
pentru n=8 fractia este echiunitara
