Toán Lớp 7: 3/4-14/5.x=2/5 chỉ e vs ạ phân số |x-3/5|+1,25=3

Question

Toán Lớp 7:  3/4-14/5.x=2/5 chỉ e vs ạ phân số |x-3/5|+1,25=3

lanngocha · Answer

a) frac{3}{4} -  frac{14}{5} . x =  frac{2}{5}   &rArr;  frac{14}{5} . x =  frac{3}{4} -  frac{2}{5} =  frac{7}{20}   &rArr; x =  frac{7}{20} :  frac{14}{5} =  frac{1}{8}   b)| x -  frac{3}{5}| + 1,25 = 3   &rArr; | x -  frac{3}{5} | = 3 - 1,25 = 1,75 =  frac{7}{4}   &rArr;  ( left[  begin{array}{l}x -  frac{3}{5} = frac{7}{4}   x -  frac{3}{5} = - frac{7}{4} end{array}  right. )   &rArr; ( left[  begin{array}{l}x= frac{47}{20}  x= frac{-23}{20} end{array}  right. ) .

daithanh · Answer

text{#Paow}     a, 3/4-14/5.x=2/5     14/5.x=3/4-2/5     14/5.x=7/20     x=7/20:14/5     x=1/8     b, |x-3/5|+1,25=3     |x-3/5|=3-1,25     |x-3/5|=7/4     C&oacute; 2 trường hợp:     +)x-3/5=7/4     x=7/4+3/5     x=47/20     +)x-3/5=-7/4     x=-7/4+3/5     x=-23/20     Vậy x=47/20 v&agrave; x=-23/20