Suppose there is a pile of quarters, dimes, and pennies with a total value of $1.06. How much of each coin can be present wit
hout being able to make change for a dollar? If there are multiple selections of coins that will work, choose the selection with the largest total number of coins.
So remember that <u>perpendicular lines have slopes that are negative reciprocals to each other</u> and <u>parallel lines have the same slope.</u> To find out if they are either parallel or perpendicular, plug the pair of points into the slope formula to find their slopes:
Since these slopes aren't the same nor are they negative reciprocals to each other, <u>the lines are neither parallel nor perpendicular.</u>