Question

Ajutati.ma va rog dau 54 de puncte + Coroana

Answer 1

a) x + 2/3 = 7/3
    x = 7/3 - 2/3 
    x = 5/3
b) 
3/7 + x = 4/7 
x = 4/7 - 3/7 
x = 1/7

c) 
3/7 - 2/35 = x 
x = 15/35 - 2/35 
x = 13/35 

d)
2 intregi si 1/5 = ( 2 x 5 + 1) / 5 =11/5
3 intregi si 1/7 = ( 3 x 7 + 1) / 7 = 21 / 7
cmmmc al numerelor ( 5 si 7) = 5 x 7 = 35
→ amplificam fractiile aducandu-le la acelasi numitor

11/5  + x = 22/7 
x = 22/7 - 11/5 
x = (5 x 22) /( 5 x 7)  - ( 7 x 11) / ( 7 x 5)
x= 110 /35 - 77/35
x = 33/35

e)
7 intregi si 1/3 = (7 x 3 + 1) /3 = 22/3 
3 intregi si 1/7 = ( 3 x 7 + 1) / 7 = 22/7
→ cmmmc al numerelor ( 3, 7 ) = 3 x 7 =21

22/3 - x = 22/7
x = 22/3 - 22/7 
x = 154/21 - 66 /21
x = 88/21
x = 4 intregi si 4/21
x= 4,19

f) 
26 /15 - x - 19/60 = 5/12
(4 x 26) - 60 x - 19 = 5 x 5
108 - 60 x = 25 + 19 
60 x = 108 - 44
60 x = 64  
x = 64/60
x = 16/15
x = 1 intreg si 1/15

g)
x - 8/3 = 1/24
x = 1/24 + 8/3
x = 1/24 + ( 8 x 8 ) / ( 8 x 3) 
x = 1/24 + 64/24
x = 65/24
x = 2 intregi si 17/24

5)
a)   4 · x = 8  ⇒ x = 8 : 4 ⇒ x = 2
b)   4 · x = 2 ⇒ x = 2/4 = 1/2
c)   2/3 · x = 4/9  ⇒ 18 x = 12 ⇒ x = 12/18 = 2/3
d)  5/7  · x = 1  ⇒ 5 x = 7  ⇒ x = 7/5

e) 
7/5 : x = 1 
7/5  × 1/x = 1 
7/5 x = 1 ⇒ 5 x = 7 ⇒ x = 7/5
f)
1/4 : x = 3/4 
1/4 · 1/x = 3/4
1/ 4 x = 3/4
12 x = 4 ⇒ x = 4/12 = 1/3
g)
1/4 : x = 3
1/4 · 1/x = 3 ⇒ 12 x = 1⇒ x = 1/12

h)
1/2  · x = 2 ⇒ x/2  = 2 ⇒ x= 2 x 2 = 4