a) 2x=6 ... x=6/2=3 ∈ N
b) 5x=2 ... x=2/5=0,4 ∉ N (nu are solutii naturale)
c) 2x/3 = 6 x=6*3/2 =9 ∈ N
d) 4x=16/5 x=16:(4*5)=4/5=0,8 ∉ N (nu are solutii naturale)
e) 9x*16=3*4 |:(3*4) ... x=1/12 ∉ N (nu are solutii naturale)
f) 3x=11-2 x= 9:3=3 ∈ N
g) 2x=20-5 x = 15:2=7,5 ∉ N (nu are solutii naturale)
h) 3x/4=12 x = (12:3)*4 = 16 ∈ N
i) 5x/2=1-1/2 x =1/2 * 2/5=1/5=0,2 ∉ N (nu are solutii naturale)
j) 5x/2 = 7/6-1/3 ... 5x/2 = (7-2)/3 ... x = 5/2 *2/5 = 1∈N
Restul cred ca poti termina conform celor de mai sus ...