Question

Calculati :
a) $[0,(5) : 2 \frac{1}{2} - 2 \frac{1}{3} ] : ( \frac{15}{24} - \frac{5}{7} ori 2 \frac{1}{3} ) - \frac{1}{2}$

b) $\frac{3}{6ori9} + \frac{3}{9ori12} + \frac{3}{12ori15} +....+ \frac{3}{21ori24}$

P.S. : Am pus "ori" in loc de semnul " · " deoarece nu mergea . Astept rezolvarile ! :)

Answer 1

a) =
[5/10:5/2-7/3]:(15/24-5/7·7/3)-1/2=
(5/10·2/5-7/3):(15/24-5/3)-1/2=
(1/5-7/3):(15-40)/24-1/2=
(3-35)/15:(-25/24)-1/2=
(-32/15)·(-24/25)-1/2=
768/375-1/2=(768·2-375)/750=1161/750=1,561(3)