Question

determine a distancia do ponto p 2,1 e a reta 3x+4y+7 = 0.

Answer 1

Dp,r = $\frac{ax+by+c}{ \sqrt{ a^{2} + b^{2} } }$
reta  3x+4y + 7 = 0 a=3, b=4, c=7 
ponto 2,1 .:. x=2 e y =1 
Dp,r = $\frac{3.2+4.1+7}{ \sqrt{9+16} }$

Dp,r = $\frac{6+4+7}{5} = \frac{17}{5}$