Question

The cost of a pack of batteries, after a 5% tax is $8.40 . What was the price before tax?

Answer 1

x +0.05x = 8.4 = 1.05x

Answer 2

Is there a proportion for it?

Answer 3

x = 8.4/1.05 = 8$

Answer 4

Wait, how'd you get that equation? @Euler271

Answer 5

let x = original price

original price + tax = $8.4

tax is calculated by a percentage of the value of the item (i know you know :P)

so it's x + (5% * x) = 8.4

and 5% = 5/100 = 0.05

so it's x + 0.05x = 8.4