Question

III. Afla 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

4 × 2 × a = 8

8 × a = 8

a = 8 : 8 = 1

b)

8 : 4 × b = 10

2 × b = 10

b = 10 : 2 = 5

c)

c : (671 - 111 × 3 × 2) = 70

c : (671 - 333 × 2) = 70

c : (671 - 666) = 70

c : 5 = 70

c = 70 × 5 = 350

d)

1000 - d × 2 - 25 × 4 = 800

1000 - d × 2 - 100 = 800

1000 - d × 2 = 800 + 100

1000 - d × 2 = 900

d × 2 = 1000 - 900

d × 2 = 100

d = 100 : 2 = 50

e)

e - 40 : 2 + 29 × 4 = 132

e - 20 + 116 = 132

e - 20 = 132 - 116

e - 20 = 16

e = 16 + 20 = 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 = 2345