Im confused on this by the way the book is named ECHO.

what you do is find out what the book is about or its Theme then find things that prove the book is about or that support the Theme.

Explanation:

Hope this helps!

this is the answer , p = 1 + (1/10)x

step-by-step explanation:

we have,

at sea level pressure is 1 atmosphere (i.e at x =0, p0=1 atmosphere)

at depth 23 meters , pressure = 3.3 atmosphere

since the pressure increases at constant rate as the depth increases, so we can write a relation as:

p =p0 +   kx   , where p is the pressure  , p0 is the initial pressure, x is the depth and k is constant rate of increasing.

to find constant rate k, plug p = 3.3 , p0 = 1 and x= 23 meters

we get,

  3.3 = 1 + k * 23

k = 2.3 / 23   = 1/10

so we can write the function formula as:   p = 1 + (1/10)x

- a.) the man dies after he is unable to keep a fire lit.