Toán Lớp 7: câu 1 5/2x -1/3=4/3 b, |2x+0,5|=8,5

Question

Toán Lớp 7:  câu 1 5/2x -1/3=4/3 b, |2x+0,5|=8,5

kymmailien · Answer

$#Ben$     Đ&aacute;n &aacute;n+Giải th&iacute;ch:      a) 5/2x - 1/3=4/3     5/2x = 4/3+1/3     5/2x = 5/3     x = 5/3 : 5/2     x = 5/3 . 2/5     x = 2/3     b) |2x-0,5|=8,5     *TH_1:     2x-0,5=8,5     2x=8,5+0,5     2x=9     x= frac{9}{2}     *TH_2     2x-0,5=-8,5     2x=-8,5+0,5     2x=-8     x=-4     Vậy x=9/2 hoặc x=-4

hiennhi98 · Answer

a) 5/2x - 1/3=4/3   5/2x = 4/3+1/3   5/2x = 5/3   x = 5/3 : 5/2   x = 5/3 . 2/5   x = 2/3   Vậy x=2/3   b) |2x-0,5|=8,5   &rArr; ( left[  begin{array}{l}2x-0,5=8,5  2x-0,5=-8,5 end{array}  right. )    &rArr; ( left[  begin{array}{l}2x=8,5+0,5  2x=-8,5+0,5 end{array}  right. )    &rArr; ( left[  begin{array}{l}2x=9  2x=-8 end{array}  right. )    &rArr; ( left[  begin{array}{l}x= frac{9}{2}  x=-4 end{array}  right. )    Vậy x=9/2 hoặc x=-4   #wcdi