Jeff can travel 2 miles in one hour
Write x-4 instead of y.
x²+(x-4)²=40
x²+x²-8x+16=40
2x²-8x-24=0
x²-4x-12=0
(x-6)(x+2)=0
x=6 or x=-2
for x=6, y=6-4 = 2
for x=-2, y=-2-4 = -6
X^3 = 16
x^3 = 4^2
x = ∛4^2
x = 4^2/3
answer
B. 4^2/3
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x^5 = 16
x^5 = 2^4
x = 2^4/5
answer
D. x = 2^4/5