It takes 7 high school students, working at identical constant individual rates, 10 hours to paint a certain house. at what time will the house be fully painted if 7 students start painting at 9 am and one student, working at the same rate, is added per hour starting at 1 pm?

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

the answer is 18 units because there are 18 small cubes inside the rectangle

hope this and p.s i am also in k12

step-by-step explanation:

12 cups   is the answer

step-by-step explanation: