Question

daca x+0.1 este media aritmetica a numerelor 10x-1.1 si 3x-3.1,atunci x are valoarea:a)0.21 b)0.1 c)0.4 d)0.44

Answer 1

(10x-1.1+3x-3.1)/2=x+0.1
13x-4.2=2*(x+0.1)
13x-4.2=2x+0.2
11x=0.2+4.2
11x=4.4=>x=4.4/11=0.4