C = 15x + 50
let c be $125 since c represents the cost
15x + 50 = 125
15x = 125 - 50
15x = $75
x = 75 ÷ 15
x = 5
4x^2-5x-14 is your answer :)
Answer:
d/dt(dx/dt)=K(dx/dt)^2
Step-by-step explanation:
Since, a is proportional to v^2; and a=d/dt(dx/dt) and v= dx/dt since they are instantanious acceleration and velocity respectively.
K=(d^x/dt^2)(dt/dx)^2
Ok so we know that y=1 so we can simply sub in the value of y into the equation :
y = -5x +3
1 = -5x +3
Move the -5x to the LHS ( Left-hand-side ) therefore it changes sign as well move 1 to the RHS ( Right-hand-side ) it also changes sign.
5x = 3 - 1
5x = 2
x = 2/5
x = 0.4
Hope this helps :).
