4x^2 + 5xy - y^2 = 6
Implicitly differentiating both sides,
4(2x) + 5(x y' + y) - 2yy' = 0
where y' = dy/dx
8x + 5xy' +5y -2yy' = 0
combining y' terms
y' (5x-2y) +8x +5y = 0
y'(5x-2y) = -(8x+5y)
dy/dx = -(8x+5y)/(5x-2y)
or
dy/dx = (8x+5y)/(2y-5x)
The slope can be found by the "rise over run", that is, is the change in variable y divided by the change in variable x.
In this question,

Substituting the values:

Answer: 0.06 feet per feet of highway.
Answer:
2,5h
if she's driving at 40 miles per hour, that means in 2 hours she will have driven 80 miles plus 30 mins. for another 20 miles. In total - 2h 30mins.
Well 58 inches is 4 feet, so Amanda has to purchase 2 yards of fabric. So this brings her to $90. If you multiply 90 by 40%, and then subtract that number from 90, you have 54. Multipy 54 by the sales tax and then add that number to 54. So Amanda will have to pay $56.75. Hope this helps, have a nice day :)
Cora earned $40 and Dora earned $60...label the graph in values of tens and plot accordingly...this might be wrong but I think it’s the best answer