Toán Lớp 7: 1. (0,5x+3) :2= (8/2)^4: (8/2)^3-3/2 2. 7/4.x+3/2=-4/5 3. [12/15+-2/7+3/15+9/7+(-5)^2]:(3/5)^2

Question

Toán Lớp 7:  1. (0,5x+3) :2= (8/2)^4: (8/2)^3-3/2 2. 7/4.x+3/2=-4/5 3. [12/15+-2/7+3/15+9/7+(-5)^2]:(3/5)^2

giahan44 · Answer

Lời giải và giải thích chi tiết:    1. (0,5x+3) :2= (8/2)^4: (8/2)^3-3/2    (0,5x + 3) : 2 = 4 - 3/2   (0,5x + 3) : 2 = 5/2   0,5x + 3 = 5/2 x 2   0,5x + 3 = 5   0,5x = 5 - 3   0,5x = 2   x = 2 : 0,5    x = 4     2. 7/4.x+3/2=-4/5    7/4.x = -4/5 - 3/2   7/4.x = -23/10   x = -23/10 : 7/4   x = -184/245    3. [12/15+-2/7+3/15+9/7+(-5)^2]:(3/5)^2    = 27 : (3/5)^2   = 75      Ch&uacute;c bạn học tốt^^

thanhbinh2k5 · Answer

1.   (0,5x+3):2=(8/2)^(4):(8/2)^(3)-3/2   &rArr;(0,5x+3):2=(8/2)^(4-3)-3/2   &rArr;(0,5x+3):2=8/2-3/2   &rArr;(0,5x+3):2=5/2   &rArr;0,5x+3=5   &rArr;0,5x=2   &rArr;x=4   Vậy x=4   2.   7/4x+3/2=-4/5   &rArr;7/4x=-4/5-3/2   &rArr;7/4x=-23/10   &rArr;x=-46/35   Vậy x=-46/35   3.   [12/15+(-2/7)+3/15+9/7+(-5)^2]:(3/5)^2   =[(12/15+3/15)+(-2/7+9/7)+25]:(3/5)^2   =(1+1+25):(9/25)   =27:(9)/25   =(27.25)/9   =(9.3.25)/9   =3.25   =75