va roog,dau coroana!!!

Hei! :)
x8- numerele cautate
a) 4
{28; 48; 68; 88}
=> x= {2, 4, 6, 8}
b) 7
{28; 98}
=> x={2, 9}
c) 11
{88}
=> x=8
d) 13
{78}
=> x=7