Eighteen men take 15 days
to dig 6 hectares of land
Find the number of men
required to dig 8 hectares
in 12 days?

number of men = 30

Step-by-step explanation:

18 men takes 15 days to dig 6 hectares of land.

18 men will take 12 days to dig ? hectares of land

cross multiply

hectares of land = 12 × 6/15  

hectares of land = 72/15

hectares of land = 4.8 hectares

18 men will take 12 days to dig 4.8 hectares of land

? number of men will take 12 days to dig 8 hectares

cross multiply

number of men = 18 × 8/4.8

number of men = 144/4.8

number of men = 30

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form