What is the simplified form of the expression 5d^6 x d^-12

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?

What is the domain and range of each function 1. x (3, 5, 7, 8, 11) y ( 6, 7, 7, 9, 14) 2. x (-3, -1, 2, 5, 7) y (9, 5, 4, -5, -7)

Add the fractions, and simply the result to lowest terms. 2/3 + 2/7= ?