If AC=24 find the value of x Then find AB and BC

Which problem could be  solved  by evaluating the expression  7×(−3)7×-3?

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 expression is equivalent to 42x-56y