A piggy bank contains $2.10 in nickels, x, and quarters, y. The number of nickels is 2 more than 3 times the number of quarters. How many nickels are there? What is their total value?

step-by-step explanation:

first, eliminate the parenthesis:

3

x

+

2

−

4

x

second, group like terms:

3

x

−

4

x

+

2

third, combine like terms:

(

3

−

4

)

x

+

2

→

−

1

x

+

2

→

−

x

+

2

(a) the volume of the cone is 20/3 in3

hence, option a is correct.