y=kx
soda water=k orange juice
2=2k
k=1
18=1 × orange juice
orange juice=18/1
orange juice=18 cups
I find it best to switch everything exponents when taking derivatives.
F(x) = 7/x
Same as..
F(x) = 7x^-1
Take derivative..
F'(x) = -7x^-2
Plug in x = 1
F'(1) = -7(1)^-2
F'(1) = -7
2659 Dollars its pretty simple all you have to do is 2931-362 and then you get 2659
12/5 is the answer!
Hope I helped!
Ps: symbolab.com is a great calculator to help solve those type of problems :-)
Let x = cost of one skirt
Let y = cost of one coat.
We need to construct a system of equations to help us solve this problem.
Lily: $452.62 = 6x + 5y
Sis: $289.36 = 3x + 5y.
Let's solve this by elimination. Multiply the second equation by -1
Lily: $452.62 = 6x + 5y
Sis: -$289.36 = -3x + -5y. Add the equations together.
$163.26 = 3x. Divide each side by 3.
$54.42 = x. Plug this into one of our original equations.
$452.62 = 6(54.42) + 5y. Multiply 6 by 54.42
$452.62 = 326.52 + 5y. Subtract 326.52 from each side.
$126.1 = 5y. Divide each side by 5
$25.22 = y.
One coat costs $25.22
