I think you would just add 2/3 and 1/3 to get 1 full can of paint. If not sorry.
It’s 9b it’s just 4+5 with the b
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)
The answer to your question is "1,200 cm".