Question

18. ! Calculați în modul cel mai convenabil:
a) 417×38+(583×11+583×27);
b)12:17+35×13+17×23;
c) (37×26+ 58×34) +21×26;
d) ((2doi sus)trei sus×74+102×10)+64×26.

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Answer 1

Răspuns:

a)

417×38+(583×11+583×27) =

417 x 38 + 583 x (11 + 27) =

417 x 38 + 583 x 38 =

38 x (417 + 583) =

38 x 1000 =

38000

b)

12x17+35×13+17×23 =

17 x (12 + 23) + 35 x 13 =

17 x 35 + 35 x 13 =

35 x (17 + 13) =

35 x 30 =

105

c)

(37×26+ 58×34) +21×26  =

26 x (37 + 2x34) + 21 x 26 =

26 x (37 + 68) + 21 x 26 =

26 x 104 + 21 x 26 =

26 x (104 + 21) =

26 x 125 =

3250

d)

((2doi sus)trei sus×74+102×10)+64×26 =

(4^3 x 74 + 102 x 10) + 64 x 26 =

64 x 74 + 102 x 10 + 64 x 26 =

64 x (74 + 26) + 102 x 10 =

64 x 100 + 102 x 10 =

10 x (640 + 102) =

10 x 742 =

7420