How to solve numbers 4-5

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?

In an isosceles triangle, the vertex angle is 112 degrees. what is the measure of each base. a.34 b.24 c.44 d.54

In july, the average temperature in one us city was 29°c. by december, the average temperature had fallen by 29°c. explain why the average temperature in december was 0°c.