a) x - $\frac{3}{4}$ = $\frac{1}{9}$
=> x = $\frac{1}{9}$ + $\frac{3}{4}$
=> x = $\frac{4}{36}$ + $\frac{27}{36}$
=> x = $\frac{31}{36}$
Vậy x = $\frac{31}{36}$ .
b) x - 8 = 50% - x
=> x - 8 = $\frac{50}{100}$ - x
=> x - 8 + x = 0,5
=> x + x = 0,5 + 8
=> 2x = 8,5
=> x = 8,5 : 2
=> x = 4,25
Vậy x = 4,25