Răspuns:
13)
a.A={2,3,4,5}
B={x,5,3,4}
x=2
b.3x-2=19
3x=19+2=21
x=21÷3
x=7
c.A={3^x,2^4,4^3,7^2}
B={16,27,49,64}
x=3
3^3=27
