Tickets to a play are priced as follows: Adult tickets: £12
Child tickets: £6
Cheryl rings the booking office to buy 6 adult tickets and 3 child tickets.
She is told that a 10% booking fee will be added to the ticket price.
2% will then be added if she is paying by credit card.
Work out the total charge that Cheryl will pay if she uses her credit card
to buy the tickets.

100.98

Step-by-step explanation:

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