Noah is buying a pair of jeans and using a coupon for 10% off. The total price is $56.70, which includes $2.70 in sales tax. Noah's purchase can be modeled by the equation: x - 0.1x + 2.70 = $56.70
$56.70 take away the tax first which brings you to $54 then 54x.10% is 5.40 so take 5.40 away from $54 you then have $48.60 then you can add the tax back in +2.70 = $51.30
