Răspuns :
amplifici 3/7 cu 4 si 1/4 cu 7
(12/28-7/28) / 15/28 = [(2²)³ : 2⁵] / ( x-2)
5/28 : 15/28 = [2⁶ : 2⁵] / (x-2)
5/28 * 28/15 = 2 /(x-2)
1/3 = 2 /(x-2) produsul mezilor = produsul extremilor
1*(x-2) = 3*2
x-2 = 6
x = 8
Răspuns:
(x-2)·(⁴⁾3/7-⁷⁾1/4)=[(2²)³:2⁵]·15/28
(x-2)·(12/28-7/28)=2⁶⁻⁵·15/28
(x-2)·5/28=30/28
(5x-10)/28=30/28
28(5x-10)=28·30
140x-280=840
140x=840+280
x=1120:140
x=8