Answer:
The provided equation is an identity.
Step-by-step explanation:
Marcos has 6 nickels and 9 quarters
<em><u>Solution:</u></em>
Let "n" be the number of nickels
Let "q" be the number of quarters
<em><u>Marcos had 15 coins in nickels and quarters</u></em>
Therefore, we can say,
number of nickels + number of quarters = 15
n + q = 15 -------- eqn 1
<em><u>He has three more quarters than nickels</u></em>
Number of quarters = 3 + number of nickels
q = 3 + n -------- eqn 2
Eqn 1 and eqn 2 represents the system of equations
<em><u>Substitute eqn 2 in eqn 1</u></em>
n + 3 + n = 15
2n + 3 = 15
2n = 15 - 3
2n = 12
<h3>n = 6</h3>
<em><u>Substitute n = 6 in eqn 2</u></em>
q = 3 + 6
<h3>q = 9</h3>
Thus Marcos has 6 nickels and 9 quarters
X = -4 -> y = 4
x = 1 -> y = -1
So, rate = (4-(-1)) / (-4-1) = -1
