( 2х + 1 )^2 - 3( х - 5 )^2 = ( 3 + х )( х - 3 )
4х^2 + 4х + 1 - 3х^2 + 30х - 75 = х^2 - 9
х^2 + 34х - 74 = х^2 - 9
34х = 65
х = 65/34
х = 1 31/34
658:7=94 836:4=209
9235+4*(536:8)=268+9235=9503
(2010-1065):7*6=945:7*6=810
40077*7-199099=280539-199099=81440
9020*6+53901=54120+53901=108021
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25/8 х
------- = ------
15/4 3/5
(25•3)/(8•5) = 15/4 х
15/8 = 15/4 х
х = (15•4)/(8•15)
х = 1/2