The gradient of a line joining (4,q) to (6,5) is twice the gradient of line joining (0,0) to (4,q). Find q

Respuesta :

Answer:

q = 2.5

Step-by-step explanation:

calculate the gradients ( slopes ) m of the 2 lines using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (4, q ) and (x₂, y₂ ) = (6, 5 )

m = [tex]\frac{5-q}{6-4}[/tex] = [tex]\frac{5-q}{2}[/tex]

repeat with (x₁, y₁ ) = (0, 0 ) and (x₂, y₂ ) = (4, q )

m = [tex]\frac{q-0}{4-0}[/tex] = [tex]\frac{q}{4}[/tex]

Then

[tex]\frac{5-q}{2}[/tex] = 2 × [tex]\frac{q}{4}[/tex] = [tex]\frac{q}{2}[/tex] ( cross- multiply )

2(5 - q) = 2q

10 - 2q = 2q ( add 2q to both sides )

10 = 4q ( divide both sides by 4 )

2.5 = q