Let T be total number of milligrams of vitamin C in our salad.
We have been given that there are s milligrams of vitamin C per milliliter of spinach, B mg per milliliter of berries, and D mg per milliliter of dressing.
Let us find how much mg of vitamin C our each ingredient of salad will have.
We have been given that a salad contains 300 milliliters of spinach, 200 ml of berries, and 42 ml of dressing.
[tex]\text{Mg vitamin C in 300 ml spinach}=300\cdot\text{s mg}[/tex]
[tex]\text{Mg vitamin C in 200 ml berries}=200\cdot\text{B mg}[/tex]
[tex]\text{Mg vitamin C in 42 ml dressing}=42\cdot\text{D mg}[/tex]
To find total milligrams of vitamin C in our salad we will add milligrams of vitamin C in each of three ingredients of salad.
[tex]T=(300s+200B+42D)\text{ mg}[/tex]
Therefore, our desired expression will be [tex]T=(300s+200B+42D)\text{ mg}[/tex].
