Question

Tìm số tự nhiên x biết:

a) (x + 1/3) : 4/5 = 5/2

b) ( x - 1/3) * 1/2 = 1/3

c) 12 1/2 + 15 3/6 < x < 4 2/5 * 1/2

d) 575 - (6x * 70) = 445

e) 8,75 * x + 3,75 * x + 28,7

f) 3/4 * x = 1/4 + 0,75

Answer 1

a) (x + 1/3) : 4/5 = 5/2

x+1/3=5/2*4/5

x+1/3=2

x=2-1/3

x=5/3

b) ( x - 1/3) * 1/2 = 1/3

x-1/3=1/3:1/2

x-1/3=2/3

x=2/3+1/3

x=1

c) 12*1/2 + 15*3/6 < x < 4*2/5 * 1/2

27/2<x<4/5

vì 27/2>4/5 nên đề sai

d) 575 - (6x * 70) = 445

6x*70=575-445

6x*70=130

6x=130:70

6x=13/7

x=13/7:6

x=13/42

e) 8,75 * x + 3,75 * x + 28,7(thiếu dữ kiện)

f) 3/4 * x = 1/4 + 0,75

3/4*x=1

x=1:3/4

x=4/3

**** nhé

Answer 2

a) (x + 1/3) : 4/5 = 5/2

x + 1/3 = 5/2 . 4/5

x + 1/3 = 2

x = 2 - 1/3

x = 5/3