a, 3/7 - 1/21 x = 1/3 . b, 7/6 - x : 3/4 = 1/12 . c, ( x- 2/7 ) ( x+ 3/4 ) = 0 . d, ( - 5/4 x + 3,25 ) . [ 3/5 - ( -5/2 x ) ] =0
Loga
Sinh Học lớp 12
