A certain drug is made from only two ingredients: compound A and compound B. There are 3 milliliters of compound A used for every 5 milliliters of compound B. If a chemist wants to make 576 milliliters of the drug, how many milliliters of compound A are needed?

216 milliliters of compound A are needed.

Step-by-step explanation:

There are two unknowns for the constituents of the final  576 milliliters of the drug:

amount of compound A (which we name A), and

amount of compound B (which we name B)

So we know two things that can be written in equation form;

1) there are 3 milliliters of A every 5 milliliters of B:

2) the chemist mixes 576 milliliters of the drug:

So we now replace  B with its expression in terms of A (from our first equation) in the second equation, and solve for A:

So 216 milliliters of compound A are needed.

21.4 i did it already for s1

step-by-step explanation: