Question

2.5(15)+3.(21)=?
11.(12)-4.(23)=?
7.(8)-3.4(5)=?

Answer 1

a) 11,(12) - 4,(23) = 1112-11/99 - 423-4/99 = 1101/99 - 419/99 = 682/99
b) 2,5(15) + 3,(21) = 2515-25/990 + 321-3/99 = 2490/990(simplificam prin 10) + 318/99 = 249/99 + 318/99 = 567/99
c) 7,(8) - 3,4(5) = 78-7/9 - 345-34/90 = 71/9 - 311/90 (Prima fractie o amplificam cu 10) => 710/90 - 311/90 = 399/90

Sper ca te-am ajutat!