The commutative property of multiplication.
First add the prices of the original books.
2.5+4.95+6=11.45
Find 20% of 11.45
=2.29
Therefore I saved $2.29
1 feet = 12 inches
1 min = 60 s
1 feet/min = 12 in/60 s = 1 in/5 s = 0.2 in/s
slope (m ) =
, y - 1 =
( x - 2)
The equation of a line in ' point- slope form 'is
y - b = m (x - a)( m is the slope and (a , b ) a point on the line )
To calculate m use the ' gradient formula'
m = (y₂ - y₁ )/(x₂ - x₁ )
let (x₁, y₁ ) = (2 , 1) and (x₂, y₂ ) = (14 , 31) ← values chosen from table
m = (31 - 1 )/(14 - 2 ) =
= 
equation in point- slope form using m =
and (a,b )= (2 , 1)
y - 1 =
( x - 2)