Надо найти значение х 5(х+2)/2=9х/4
5( x + 2 ) / 2 = 9x / 4 ( 5x + 10 ) / 2 = 9x / 4 2( 5x + 10 ) / 4 = 9x / 4 2( 5x + 10 ) = 9x 10x + 20 = 9x x = - 20