Question

You have a total of 21 coins that are nickels and quarters. The coins have a value of $2.25. How many quarters do you have?

Answer 1

Answer:  6

Step-by-step explanation:

Let n represent the quantity of nickels and q represent the quantity of quarters, then set up a system of equations and solve for q.

Quantity:  n  +    q  =  21    →    -5(n  +    q  =  21)    →   -5n    -5q  = -105

 Value:   5n + 25q = 225  →    1(5n + 25q = 225)  →    5n + 25q = 225

                                                                                              20q  = 120

                                                                                                   q  =  6

Answer 2

Answer:

Step-by-step explanation:

Let n represent the quantity of nickels and q represent the quantity of quarters, then set up a system of equations and solve for q.

Quantity:  x  +    y  =  21    →    -5(x  +    y  =  21)    →   -5x    -5y  = -105

Value:   5nx+ 25y = 225  →    1(5x + 25y = 225)  →    5x + 25y = 225

                                                                                             20y  = 120

                                                                                                  y  =  6