1/3*1/4(7/8х-3/4)=1/2+3/4(-1/3х+4/9) 50

1/3 * 1/4*(7/8х - 3/4) = 1/2 + 3/4*(-1/3х + 4/9)
1/3 * (7/32х - 3/16) = 1/2 - 1/4х + 1/3
7/96х - 1/16 = 1/2 - 1/4х + 1/3
7/96х - 1/16 - 1/2 + 1/4х - 1/3 = 0
7/96х - 6/96 - 48/96 + 24/96х - 32/96 = 0
31/96х - 54/96 - 32/96 = 0
31/96х - 86/96 = 0
31/96х = 86/96
х = 86/96 : 31/96
х = 86/96 * 96/31
х = 86/31
х = 2 24/31

ответ: 2 24/31