Arecipe calls for 5 deciliters of water and 236 milliliters of milk. how many milliliters of liquid does the recipe call for in total?

1 deciliter is one-tenth of a liter and 1 milliliter is one-thousandth of a liter.
So: 1 liter = 10 deciliter = 100 centiliter = 1000 milliliter

This means that 1 deciliter is equal to 100 milliliters.
Based on the above:

5 deciliters = 500 milliliters
500+236 = 736

The recipe calls for 736 milliliters of liquid in total.

X+7.5=28.5
X=28.5-7.5
X=21