3/4(0,5х + 2/3) = 3х + 2 1/4
3/4 * 0,5х + 3/4 * 2/3 = 3х + 2 1/4
3/4 * 5/10х + 1/2 = 3х + 2 1/4
3/8х + 1/2 = 3х + 2 1/4
3/8х - 3х = 2 1/4 - 1/2
3/8х - 24/8х = 2 1/4 - 2/4
- 21/8х = 1 5/4 - 2/4
- 21/8х = 1 3/4
х = 1 3/4 : (- 21/8)
х = 7/4 * (- 8/21)
х = 1/1 * (- 2/3)
х = - 2/3