Eight less than a number doubled is twenty more than the number. what is the number?

Can some one me, i’ve been asking for so long

Adaylily farm sells a portion of their daylilies and allows a portion to grow and divide. the recursive formula an=1.5(an-1)-100 represents the number of daylilies, a, after n years. after the fifth year, the farmers estimate they have 2225 daylilies. how many daylilies were on the farm after the first year?

Determine which expressions represent real numbers and which expressions represent complex number. asaaap! plis!