Given
gas prices are now $3.75 and it up 10% from 6 months ago.
Find out how much were gas prices 6 months ago.
To proof
gas prices now = $3.75
let the gas price 6 month ago = x
gas price now is rise up 10% from 6 months ago
First write 10% in simpler form
= 0.1
Now the equation becomes
0.1x + x = 3.75
1.1x = 3.75
x = 3.41 (approx)
Thus gas prices 6 months ago be $ 3.41 (approx )
Hence proved