A scuba diver is swimming at the depth shown(-46 feet), and then swims 0.5 foot toward the surface every 3 seconds. What is the location of the scuba diver, relative to the surface, after 15 seconds?

Let's solve this system of equation by substitution, alright?
A)
Step 1
Substitute "y= 4x-1"
[4x-1=8x-9}
Step 2
Isolate x for 4x-1 = 8x-9
• 4x-1 = 8x-9
Add 1 to both sides
• 4x-1+1 = 8x-9+1
Simplify
• 4x = 8x-8
Subtract 8x from both sides
• 4x-8x = 8x-8x-8
Simplify
• -4x = -8
Divide both sides by -4
• -4x/4 = -8/4
Simplify
• x = 2

For y = 4x-1
Substitute x=2
Therefore; y = 4(2)-1
                   y= 8-1
                   y= 7

Solution: x = 2, y = 7
B) The lines representing the two equations would intersect at (2,7). This is true because both coordinate points fulfill the equations shown above