Question

5x[1/2+(7/24-5/36):55/72]=?

Answer 1

5 x [ 1/2 + ( 7/24 - 5/36 ) : 55/72 ]=
= 5 x [ 1/2 + ( 21/72 - 10/72) : 55/72] =  
= 5 x ( 1/2 + 11/72 x 72/55) =
= 5 x ( 1/2 + 1/5 ) =
= 5 x ( 5/10 + 2/10 ) =
= 5 x 7 / 10 =
= 7/2=
= 3 intregi si 1/2=
= 3, 5 

Obs:
→ cmmmc al numerelor ( 24, 36) = 2³×3²=72
→ aduc fractiile la acelasi numitor comun 72, amplificand prima fractie din paranteza rotunda cu 3, iar a doua fractie cu 2
(3 x 7) / ( 3 x 24) = 21/72
( 2 x 5 ) / ( 2 x 36) = 10/72
→ diferenta parantezei rotunde = 11/72, pe care o inmultesc cu fractia 72/55
→ simplific pe 72 cu 72 , dar si pe 11 cu 55 = 1/5
→ cmmmc al numerelor ( 2, 5 ) = 10
→ amplific fractia 1/2 cu 5, iar pe 1/5 cu 2 = 7/10
→ simplific pe 5 cu 10 = 1/2 × 7
→ extrag intregii din fractia 7/2

Answer 2

5x[1/2+(7/24-5/36):55/72]=
5x[1/2+(7/24-5/36)x72/55]=
                n.c.=72
5x[1/2+(21-10)/72x72/55]=
5x(1/2+11/72x72/55)=
5x(1/2+1/5)=
       n.c.=10
5x(5+2)/10=
5x7/10=7/2=3,5