The answer is c)4 the four step of the problem solving process
Answer:
Discount percentage is 16.4% for the customers who purchase 6- coupon book .
Step-by-step explanation:
Formula

As given
Your station charges $15.95 for an oil change.
Original charge of the oil change for 6 times = 6 × Original charge for oil change .
= 6 × 15.95
= $ 95.7
As a promotion you sell six coupons for oil changes for $80.
Discount = Original charge of the oil change for 6 times - Charge by six coupons for oil changes .
= $95.7 - $80
= $ 15.7
Putting all the values in the above



Discount percentage = 16.4%
Therefore the discount percentage is 16.4% for the customers who purchase 6- coupon book .
we are given

we can use vertex form parabola formula

so, we can complete x square




so, option-A........................Answer

Divide both sides of the inequality by 4

Move the constant to the right-hand side and change its sign

Calculate the difference

And we are done solving!!~