Any has set(s) of physical and chemical properties.
a.
pure substance; multiple
b.
pure substance; one
c.
mixture; one
d.
mixture; two

pure substance, one

Explanation:

Pure substances are classified as substances that have a set of chemical and physical properties that present themselves constantly and do not change under the influence of pressure and temperature. These substances are divided into simple substances (formed by a single element, such as N2) and compound substances (formed by two or more elements, such as HCl).

x=3 and y=1

Step-by-step explanation:

Let's solve your system by substitution.

x=3y;2x+4y=10

Step: Solvex=3yfor x:

x=3y

Step: Substitute3yforxin2x+4y=10:

2x+4y=10

23y+4y=10

10y=10(Simplify both sides of the equation)

10y

10

=

10

10

(Divide both sides by 10)

y=1

Step: Substitute1foryinx=3y:

x=3y

x=(3)(1)

x=3(Simplify both sides of the equation)

x=3 and y=1