How does your figure look like?
You would simply add the last two equations together. If v=2x+1 and t=4x-1, you can add them up. This would make 2x+1+4x-1. If you combine like terms, 1 and -1 cancel out and you are left with 6x. This means x can be anything.
Is it 80 m I think that’s the answer
So y=mx+b
m=slope
y=-3x+b
subsitutue 1 for x and 4 for y
4=-3(1)+b
4=-3+b
add 3 to both sides
7=b
the equaiton is y=-3x+7