When Lucy left her house in the morning, her cell phone battery was partially charged. Lucy's phone lost battery life at a rate of 8% each hour and 3 hours after leaving her house, the battery had 16% remaining battery life. Write an equation for B, B, in terms of t, t, representing the charge remaining in Lucy's battery, as a percentage, tt hours after Lucy left her house.

B=-8t+40

Step-by-step explanation: I just did it

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

answer is 270 degrees: -

to convert radians to degrees you multiply by 180/π

9π/ 6 * 180 / π

=   9 * 180 / 6

= 9 * 30

=   270 degrees   answer