Question

Aflati x din proportiile urmatoare scriind rezultatul sub forma de fractie ordinara: a)x/9 =19/8a5 bara deasupra unde 8a5 bara deasupra se divide cu 9 b)x+1/16=12/13a bara deasupra unde 13a bara deasupra se divide cu 4 c)3x-1/15=24/18a bara deasupra unde 18a bara deasupra se divide cu 5 d)2x/15=24/19a bara deasupra unde 19a bara deasupra se divide cu 12 e)x/17=22/56a bara deasupra unde 56a bara deasupra se divide cu 11 f)x/14=26/18a bara deasupra unde 18a bara deasupra se divide cu 13

Answer 1

a)x/9 =19/8a5 bara deasupra unde 8a5 bara deasupra se divide cu 9
8a5 divizibil cu 9  8+a+5 divizibil cu 9 deci : a=5 855:9=95 x/9=19/855 x=9*19/855=1/5

b)(x+1)/16=12/13a bara deasupra unde 13a bara deasupra se divide cu 4
a=2  132 :4=33
(x+1)/16=12/132=1/11
11x+11=16
11x=5
x=5/11
a=6  136 :4=34
(x+1)/16=12/136=3/34
34x+34=48
34x=14
x=14/34=7/17


c)(3x-1)/15=24/18a bara deasupra unde 18a bara deasupra se divide cu 5
a=0  180:5=36
(3x-1)/15=24/180=2/15
3x-1=2
x=1
a=5    185:5=37
(3x-1)/15=24/185    (3x-1)/3=24/37
37(3x-1)=3*24
111x-37=72
111x=109
x=109/111
x=1

d)2x/15=24/19a bara deasupra unde 19a bara deasupra se divide cu 12
a=2  192:12=16
2x/15=24/192=1/8
x=15*1/2*8=15/16

e)x/17=22/56a bara deasupra unde 56a bara deasupra se divide cu 11
a=1 561:11=51
x/17=22/561=2/51
x=2*17/51=2/3

f)x/14=26/18a bara deasupra unde 18a bara deasupra se divide cu 13 a=2    182:13=14
x/14=26/182
x/14=1/7  x=14/7=2