Equation of straight line I know,
$Ax + By = C$
is the equation of straight line but a different resource says that: 
$y = mx + b$ 
is also an equation of straight line? Are they both same?

$Ax + By = C$
$By = -Ax + C$
$y = -(A/B)x + C/B$
Let $m = -\frac{A}{B}$.  Let $b = \frac{C}{B}$.
$y = mx + b$
So they are equivalent. 
