Question

Calculati :c)2,75+0,08(3)-1(2)=?, f) -0,69(4)+1(6)-1,875=? VA ROGG DAU 71 DE PUNCTE

Answer 1

2,75 + 0,08(3) - 1,(2) =

= 275/100 + (83-8)/900 - (12-1)/9 =

= 275/100 + 75/900 - 11/9 =

= 9×275/900 + 75/900 - 11×100/900 =

= 2475/900 + 75/900 + 1100/900 =

= 3650/900 =

= 4,0(5)


- 0,69(4) + 1,(6) - 1,875 =

= - (694- 69)/900 + (16-1)/9 - 1875/1000 =

= - 625/900 + 15/9 - 1875/1000 =

= -( 625×10)/9000 + 15×1000/9000 - 9×1875/9000 =

= - 6250/9000 + 15000/9000 - 16875/9000 =

= 8750/9000 - 16875/9000 =

= - 8125/9000 =

= - 0,902(7)