Answer:
18
Step-by-step explanation:
answer is C
the second one , why? because 7a-12a=-5a
4 - 8 = -4
so 20% of the total price equals $ 30
let x represent the total price
turn ur percent to a decimal
0.20x = 30
x = 30 / 0.20
x = 150 <=== total price
The answer should be: r ≈ 8.21