See the attached picture:
6% = 1200
9% = 2400
12% = 3800
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.
Answer:
The solution of the system of equations is (11, 12)
Step-by-step explanation:
∵ The price of each student ticket is $x
∵ The price of each adult ticket is $y
∵ They sold 3 student tickets and 3 adult tickets for a total of $69
∴ 3x + 3y = 69 ⇒ (1)
∵ they sold 5 student tickets and 3 adults tickets for a total of $91
∴ 5x + 3y = 91 ⇒ (2)
Let us solve the system of equations using the elimination method
→ Subtract equation (1) from equation (2)
∵ (5x - 3x) + (3y - 3y) = (91 - 69)
∴ 2x + 0 = 22
∴ 2x = 22
→ Divide both sides by 2 to find x
∵ 
∴ x = 11
→ Substitute the value of x in equation (1) or (2) to find y
∵ 3(11) + 3y = 69
∴ 33 + 3y = 69
→ Subtract 33 from both sides
∵ 33 - 33 + 3y = 69 - 33
∴ 3y = 36
→ Divide both sides by 3
∵ 
∴ y = 12
∴ The solution of the system of equations is (11, 12)