Help plsss If d = c-b / a-n , then wbat is the value of b?
A) c-d / a-b
B) ca-d / ca+d
C) c-ad / 1-d
D) c+ad / d-1

Two blends of tea are mixed to make a blend that will be sold at the fair. black tea sells for $2.20 per pound and orange pekoe tea sells for $3.00 per pound. how much of each should be used to obtain a 4lb blend selling for $2.50 per pound?