You and 3 friends are going to the fair. You have a coupon that will save your group $20. If the total bill to get into the fair was $100, how much does one regular priced ticket to the fair cost? Equation:

one regular ticket costs $30

Step-by-step explanation:

The total number of people = 4

Without  the $20 coupon, the total cost would have been =100+20 = $120

Assume the price of one regular ticket is x;

4x = 120

Divide both sides by 4 to solve for x

x = 120/4

x = 30

Therefore, one regular ticket costs $30

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15