Answer:
The original cost is $350
Step-by-step explanation:
Let's assume
original cost of computer is x
There is a 10% off sale on laptop computers
So, amount saved is

now, we are given
someone saves $35 on a laptop
so, we can set them equal
and then we can solve for x

we can divide both sides by 0.10
and we get

So,
The original cost is $350
V= x*(10-2x)(8-2x)
for greatest volume, differentiate v w.r.t x and equate to 0,
dv/dx= (10-2x)(8-2x) + x(-2)(8-2x)+ x(10-2x)(-2)=0
you get x from solving the quadratic equation. volume will be max at that x
9^2 < 6^2 + 8^2
so its acute angled.
2x dx/dt +2y dy/dt = 0
<span>x dx/dt + y dy/dt = 0 </span>
<span>9*4 + 12 dy/dt = 0 </span>
<span>dy/dt = - 3 ft/sec </span>