I need help with this please!

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?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

To convert celsius temperatures to fahrenheit, you can use the expression (c + 32). tom says that another way to write this expression is c + 32. what error did tom make?