find the equation of a straight line passing through
points (h,0)and (0,k) if the point (3,3) lies on the same line
prove
that 1/h+1/k=1/3​

Respuesta :

Answer:

see explanation

Step-by-step explanation:

The equation of a line in slope- intercept form is

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

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (h, 0) and (x₂, y₂ ) = (0, k)

m = [tex]\frac{k-0}{0-h}[/tex] = - [tex]\frac{k}{h}[/tex]

note the line crosses the y- axis at (0, k) ⇒ c = k

y = - [tex]\frac{k}{h}[/tex] x + k ← equation of line

Given that (3, 3) lies on the line then

3 = - [tex]\frac{3k}{h}[/tex] + k ( add [tex]\frac{3k}{h}[/tex] to both sides )

3 + [tex]\frac{3k}{h}[/tex] = k ( multiply through by h to clear the fraction )

3h + 3k = hk ← factor out 3 on the left side

3(h + k) = hk ← divide both sides by hk )

[tex]\frac{3(h+k)}{hk}[/tex] = 1 ( divide both sides by 3 )

[tex]\frac{h+k}{hk}[/tex] = [tex]\frac{1}{3}[/tex], that is

[tex]\frac{h}{hk}[/tex] +[tex]\frac{k}{hk}[/tex] = [tex]\frac{1}{3}[/tex]

[tex]\frac{1}{k}[/tex] + [tex]\frac{1}{h}[/tex] = [tex]\frac{1}{3}[/tex] ← as required