15 a merchant blends tea that sells for $4.30 a pound with tea that sells for $2.10 a pound to produce 110 lbs of a mixture that sells for $3.80 a pound. how many pounds of each type of tea does the merchant use in the blend?

First calculate the total sales of a mixture
Total sales=110×3.8=418

Now set the equation
4.3x+2.1 (110-x)=418
Solve for x
4.3x+231-2.1x=418
4.3x-2.1x=418-231
2.2x=187
X=187÷2.2
X=85 pounds sells for 4.3

110-85=25 pounds sells for 2.1

Hope it helps!

C. expression because any expression or equation may contain more than one variable