Awater tank is 3/4 full. 56 litres of water are taken from the tank. the tank is now 2/5 full. show clearly that the tank holds 160 litres when full.

x/.75=x-56/0.4

0.4x=.75x-42

-0.35x=-42

x=120

I set up a proportion in which x=the tank when it is 3/4 full. When the tank is 3/4 full, solving the proportion tells us the x=120 litres. 120/3=40, and 120+40 is 160, showing that a tank completely full would indeed hold 160 litres.

Hope this helps!

A.    The y intercept is 4500 and it represents his altitude when the observer started to time him. 

B.    The slope is -1500. he is descending at a rate of 1500ft a minute

C.    The x-intercept is 3. It means that he will hit the ground in 3 minutes.

D.    The equation in slope-intercept form is y=-1500x+4500