A line segment is precisely defined using the undefined terms point and plane. These three terms are undefined terms in geometry. A point has no dimension. A plane has no thickness but extends at all directions. A line has no thickness but extends in one dimension
Let x = cost of one skirt
Let y = cost of one coat.
We need to construct a system of equations to help us solve this problem.
Lily: $452.62 = 6x + 5y
Sis: $289.36 = 3x + 5y.
Let's solve this by elimination. Multiply the second equation by -1
Lily: $452.62 = 6x + 5y
Sis: -$289.36 = -3x + -5y. Add the equations together.
$163.26 = 3x. Divide each side by 3.
$54.42 = x. Plug this into one of our original equations.
$452.62 = 6(54.42) + 5y. Multiply 6 by 54.42
$452.62 = 326.52 + 5y. Subtract 326.52 from each side.
$126.1 = 5y. Divide each side by 5
$25.22 = y.
One coat costs $25.22
