The -9 because absolute value is the number itself without positive or negative. So it’s the 9. Hope this helps!
Answers:
Option 1)
6a + 8s = 102
14a + 4s = 150
each adult ticket costs 9 dollars
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Explanation:
6 adult tickets and 8 student tickets bring in $102, so that means 6a+8s = 102
14 adult tickets and 4 students tickets bring in $150, so 14a+4s = 150
The system of equations is

If we multiply both sides of the second equation by -2, we get this updated system

Add the equations straight down
6a+(-28a) = -22a
8s+(-8s) = 0s = 0 ... the 's' terms go away
102+(-300) = -198
So we end up with the equation -22a = -198 and that solves to a = 9 after dividing both sides by -22.
Each adult ticket costs $9
If you want the value of s, then
6a+8s = 102
6(9)+8s = 102
54 + 8s = 102
8s = 102-54
8s = 48
s = 48/8
s = 6
Meaning each student ticket costs $6
Or you could use the other equation
14a+4s = 150
14(9)+4s = 150
126+4s = 150
4s = 150-126
4s = 24
s = 24/4
s = 6
We get the same value of s
For perpendicular lines, m2 = -1/m1 = -1/(-2/3) = 3/2 [m1 = -2/3]
Required equation is y + 2 = 3/2(x + 2) => y + 2 = 3/2 x + 3 => y = 3/2 x + 1
length = 12 yd
width = 10 yd
height = 12 yd
diagonal = 19.697715603592 yd
total surface area = 768 yd2
lateral surface area = 528 yd2
bottom surface area = 120 yd2
volume = 1440 yd3
5.3 * 0.5 = 2.65
5.3/2=2.65