Let the lawn seats purchased by the business be : L
Let the reserved seats purchased by the business be : R
Given :
⊕  Cost of each lawn seat : $10
⊕  Cost of each reserved seat : $25
⊕  Sponsoring business has given the $375 to purchase seats
⊕  School purchased 30 seats using all of the money
⇒  L + R = 30     ---------- (1)
⇒  10L + 25R = 375       ----------- (2)
Multiplying equation (1) with 10, we get :
⇒  10L + 10R = 300    ------------- (3)
Subtracting equation (3) from equation (2), we get :
⇒  10L + 25R - (10L - 10R) = 375 - 300
⇒  25R - 10R = 75
⇒  15R = 75
⇒  R = 5
Substituting R = 5 in equation (1), we get :
⇒  L + 5 = 30
⇒  L = 25
Answer: The Business purchased 25 lawn seats and 5 reserved seats