Question

Rezolvati urmatoarele ecuatii,unde x este numar natural:
a)2(4x-5)=5x + 14
b)3(2x-1)=23-7x
c)4(3x-5)=2x + 10
d)5(2x-9)=3x+11
e)2x+4=(x-10)6
f)10x + 29 = (1+3x)7

Answer 1

a ) 2(4x-5)=5x + 14
8x - 10 = 5x + 14
8x -5x = 14 +10
3x = 24 
x = 24:3
x = 8 

b ) 3(2x-1)=23-7x
6x - 3 = 23 - 7x 
6x+ 7x = 23+ 3
13x = 26 
x = 26: 13
x = 2 

c ) 4 ( 3x- 5)=2x + 10
12x - 20 = 2x + 10
12x- 2x = 20 + 10 
10 x = 30 
x = 30 : 10 
x = 3 

d ) 5(2x-9 ) = 3x + 11
10x- 45 = 3x + 11
10x-3x = 45+ 11 
7x = 56
x = 56:7
x= 8

e) 2x+ 4= (x-10) 6
2x+4 = 6x - 60 
4+60 = 6x-2x
64=4x
x= 64:4
x=16

f) 10x+29 = (1+3x)7
10x+29 = 7 + 21x
29-7 = 21x-10x
22= 11x
x = 22:11
x = 2