Răspuns:
Explicație pas cu pas:
2.
a = b/10
c = d/10
e = f/10
a + c + e = b/10 + d/10 + f/10 = (b + d + f)/10
(a + c + e)/(b + d + f) = 1/10
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3.
x + y + z = 78000
x/2 = y/6 = z/5 = k
x = 2k
y = 6k
z = 5k
x + y + z = 78000
2k + 6k + 5k = 78000
13k = 78000
k = 78000 : 13 = 6000
x = 12000
y = 36000
z = 30000
_________________________
4.
x + y + z = 24,5
x/1,6 = y/3 = z/5,2 = k
x = 1,6k
y = 3k
z = 5,2k
x + y + z = 1,6k + 3k + 5,2k = 9,8k = 24,5
k = 24,5 : 9,8 = 2,5
x = 1,6*2,5 = 4
y = 3*2,5 = 7,5
z = 5,2*2,5 = 13
______________________
5.
a = 4e
b = 4f
c = 4g
d = 4h
a + b + c + d = 4e + 4f + 4g + 4h = 4(e + f + g + h)
(a + b + c + d)/(e + f + g + h) = 4
10 - (a + b + c + d)/(e + f + g + h) = 10 - 4 = 6
