Indeed, a fare of $40 is a fair charge for the cab ride.
Explanation
Sheri's cab fare totaled $32, with a gratuity rate of 20%.
The gratuity amount is: 
Thus, the total cab fare including gratuity is: 
Since Sheri issued a $40 check to the cab driver, it indicates she provided ($40 - $38.40) or an extra $1.60 to the cab driver. Consequently, the $40 payment is reasonable for the cab fare.
To tackle this problem, we first need to ascertain the commission taken by the pizza shop and how much money belongs to Mindy. We know that Mindy sells her artwork for $15, and the pizza shop retains a 15% commission. Therefore, the commission is calculated as (15/100) * 15, which equals 2.25 dollars. This means the pizza shop deducts $2.25 from each art sale made by Mindy. Consequently, the amount Mindy receives is (15 - 2.25), resulting in $12.75. Since Mindy opts not for cash but instead chooses a pizza valued at $12, including a 5% sales tax, it seems she benefits by $0.75 plus the pizza worth $12. Therefore, this arrangement appears fair for Mindy. Meanwhile, the pizza shop also makes an additional $2.25 from this transaction, making it equitable for both Mindy and the shop owner.
2x^2 - y = -5
x + y = 8
----------------adding gives us
2x^2 + x = 3 <==
** It's important to note that 2x^2 and x cannot be combined, because they are not like terms.
You might have better success by searching for answers individually:)
