2,560 gallons in 30 days

Area of the rectangle = x² - 3x - 10

2019

Step-by-step explanation:

Length of the rectangle = x + 2

Width of the rectangle = x - 5

Area of the rectangle = length × width

= (x + 2) (x - 5)

= x² + 2x - 5x - 10

= x² - 3x - 10

Area of the rectangle = x² - 3x - 10

C = 20t² + 135t + 3050

Where

C = the number of new cars

t = year the number of new cars was purchased

t = 0 corresponds to 1998

Find the when c = 15,000

C = 20t² + 135t + 3050

15,000 = 20t² + 135t + 3050

20t² + 135t + 3050 - 15,000 = 0

20t² + 135t - 11,950 = 0

4t² + 27t - 2390 = 0

Solve using quadratic equation

t = -b ± √b² - 4ac / 2a

= -27 ± √27² - 4(4)(-2390) / 2(4)

= -27 ± √729 -(-38240) / 8

= -27 ± √729 + 38240 / 8

= -27 ± √38969 / 8

= -27/8 + √38969/8 or 27/8 - √38969/8

= -3.375 + 197.41/8 or -3.375 - 197.41/8

= -3.375 + 24.67625 or -3.375 - 24.67625

t = 21.30125 or - 28.05125

t cannot be negative

Therefore,

t = 21.30125

To the nearest whole number

t = 21

Recall,

t = 0 corresponds to 1998

Therefore

1998 + 21 = 2019

c = 15,000 in the year 2019