Question

află valoarea necunoscutelor:a) 2×2×2×a=8 ; b) 8÷4×b=10; c) c÷(671-111×3×2)=70 ; d) 1000-d×2-25×4=800 ; e) e-40÷2+29×4=132 ; f) f÷7+25=900-(300-48×5)×9​

Answer 1

Răspuns:

Explicație pas cu pas:

a)

2×2×2×a=8

8×a = 8

a = 8 : 8

a = 1

________________

b)

8 : 4 × b = 10

2 × b = 10

b = 10 : 2

b = 5

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c)

c : ( 671 - 111×3×2) = 70

c : ( 671 - 333×2) = 70

c : ( 671 - 666 ) = 70

c : 5 = 70

c = 70 × 5

c = 350

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d)

1 000 - d × 2 - 25 × 4 = 800

1 000 - d × 2 - 100 = 800

1 000 - d × 2 = 800 + 100

1 000 - d × 2 = 900

d × 2 = 1 000 - 900

d × 2 = 100

d = 100 : 2

d = 50

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e)

e - 40 : 2 + 29 × 4 = 132

e - 20 + 116 = 132

e - 20 = 132 - 116

e - 20 = 16

e = 16 + 20

e = 36

___________

f)

f : 7 + 25 = 900 - ( 300 - 48 × 5 ) × 9

f : 7 + 25 = 900 - ( 300 - 240 ) × 9

f : 7 + 25 = 900 - 60 × 9

f : 7 + 25 = 900 - 540

f : 7 + 25 = 360

f : 7 = 360 - 25

f : 7 = 335

f = 335 × 7

f = 2 345