Please help with theses ? I’m kinda stuck on Algebra ll B. Anybody good on Algebra ?

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?

Can someone answer this question for me

Simplify using positive exponents only.