Answer:
I think It is 7
Step-by-step explanation:
Answer:
a = 36°
b = 144°
Step-by-step explanation:
<h3><u>Method 1</u></h3>
Number of sides = n = 10
Sum of interior angles = (n - 2) × 180°
= (10 - 2) × 180°
= 8 × 180°
= 1440°
Interior angle = b = sum of interior angles ÷ number of sides
b = 1440 ÷ 10
b = 144°
a + b = 180° (Sum of angles in the straight line)
a + 144° = 180°
a + 144° - 144° = 180° - 144°
a = 36°
<h3><u>Method 2</u></h3>
Number of sides = 10
Exterior angle = a = 360° ÷ Number of sides
a = 360° ÷ 10
a = 36°
a + b = 180° (Sum of angles in the straight line)
36° + b = 180°
36° + b - 36° = 180° - 36°
b = 144°
Answer:
10 hours
Step-by-step explanation:
(150/x) + 1.5 + (450/(x+15)) = 600/x
Multiply through by x(x + 15):
150(x + 15) + 1.5x(x + 15) + 450x = 600(x + 15)
150x + 2250 + 1.5x^2 + 22.5x + 450x = 600x + 9000
150x + 2250 + 1.5x^2 + 22.5x + 450x - 600x - 9000 = 0
1.5x^2 + 22.5x - 6750 = 0
x = (-22.5 +/- sqrt(22.5^2 - 4(1.5)(-6750))) / (2*1.5)
x = (-22.5 +/- sqrt(506.25 + 40500)) / 3
x = (-22.5 +/- sqrt(41006.25)) / 3
x = (-22.5 +/- 202.5) / 3
x = 180/3 or -225/3
x = 60 or -75
But a negative number doesn't make sense, so therefore x = 60, so the journey took 600/60 = 10 hours.
10.5 is the standard deviation for the data set to the nearest tenth hope this helps;)
Answer:
Step-by-step explanation:
