x = regular price
x + .19 = premium price
6x + 7(x + .19) = 34.09 ← substituted values
6x + 7x + 1.33 = 34.09 ← distributive
13x + 1.33 = 34.09 ← like terms
13x = 32.76 ← subtracted 1.33
x = 2.52 ← divided
x + .19 = 2.71 ← substituted
regular = $2.52
premium = $2.71
 Proof
