Question

13. Se dau numerele: x = 0,039 : [0,05. (2,31 : 0,077)],
y=0,278 : 13,9 +(2 - 0,47): 0,15, z = 29,41 - (14,46 -0,35).
Calculaţi:
a)x+y+z; b) z - y - x; c) 2x + 3y - z; d) x 100 +2,1 .y-z,​

Answer 1

Răspuns:

Explicație pas cu pas:

x = 0,039 : [0,05·(2,31 : 0,077)]

x = 39/1000 : [5/100 ·(231/100 · 1000/77)]

x = 39/1000 : [5/100 · 30/1)]

x = 39/1000 :(15/10)

x = 39/1000 · 10/15 = 390/15000⁽³⁰ = 13/500 = 0,026

sau : x = 0,039: [0,05·30] = 0,039:1,5 = 0,026

y = 0,278 : 13,9 +(2 - 0,47): 0,15

y = 278/1000 : 139/10 + 153/100 : 15/100

y = 278/1000 · 10/139 + 153/100 · 100/15

y = 2/100⁽² + 153/15⁽³ = 1/50 + ¹⁰⁾51/5 = 511/50 =>

y = 10,22

sau y = 0,278 :13,9+1,53:0,15 = 0,02+10,20 = 10,22

z = 29,41-(14,46-0,35) = 29,41-14,11 = 15,30

a) x+y+z = 0,026+10,22+15,30 = 25,546

b) z-y-x = 15,30-10,22-0,026 = 5,054

c) 2x+3y-z = 2·0,026+3·10,22-15,30 = 0,052+30,66-15,30 = 15,412

d) x·100+2,1·y -z = 0,026·100+2,1·10,22-15,30 = 2,6+21,462-15,30 =

= 8,762

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