'' '' says kuku and yaya a middle-school band holds a car wash to raise money. the sixth-grade band members wash 16 cars. the seventh-grade band members wash 75% as many cars as the sixth-graders. the eighth-grade band members wash half as many cars as the sixth- and seventh-grade band members combined. if the band charges $5 per car, how much money did the members raise altogether?

87%

step-by-step explanation:

apex answer

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