What's the difference between a linear expression and a linear equation?

Dimitri used a coupon that saved him 80 percent, or $6.87. he paid $34.35 for the items. dimitri used a coupon that saved him 80 percent, or $27.48. he paid $34.35 for the items. dimitri used a coupon that saved him 80 percent, or $6.87. the price of the items before the discount was $34.35.dimitri used a coupon that saved him 80 percent, or $27.48. the price of the items before the discount was $34.35.