Вот держи!
х/10=5/0,5
x=10*(5/0,5)-10*10=100
0.12=15+x/150+x
15+x=18+0.12x
0.88x=3
x=3/0.88=3.4
0.1=7.5+x/150+x
7.5+x=15+0.1x
0.9x=7.5
x=7.5/0.9=8.33
= ( 4y^2 - 4xy + x^2 ) - ( 4y - 2x ) = ( 2y - x )^2 - 2( 2y - x ) = ( 2y - x )( 2y - x - 2 )
(5/6+12/5) * 7,5=(25/30+72/30)*7,5=97/30*225/30=21825/900=24,25