A chemist is preparing a 1,000-milliliter solution using three different liquids: Liquid A, Liquid B, and Liquid C. The table below shows the density (grams per milliliter) and cost per milliliter for each liquid.

| Liquid | Density (g/mL) | Cost per mL ( $) ∣∣ : - - - - - - - ∣ : - - - - - - - - - - - - - ∣ : - - - - - - - - - - - - - - ∣∣ L i q u i d A ∣1.2∣0.15∣∣ L i q u i d B ∣0.8∣0.10∣∣ L i q u i d C ∣1.5∣0.20∣ T h e t o t a l v o l u m eo f t h eso l u t i o ni s 1, 000 mi ll i l i t ers . I f 300 mi ll i l i t erso f L i q u i d C a re u se d, w hi c h o f t h e f o ll o w in g e q u a t i o n sco u l d s h o wt h ere l a t i o n s hi p b e tw ee n t h e v o l u m es,$ x $an d$ y $, inmi ll i l i t ers, f ore a c h o f t h eo t h er l i q u i d s u se d ?$