# How do you write an equation of a line with point (-1,4) and slope -1?

##### 1 Answer
Nov 14, 2016

$y = - x + 3$

#### Explanation:

The general equation of the straight line is :
$\text{ }$
$y - {y}_{0} = a \left(x - {x}_{0}\right)$
$\text{ }$
$a \text{ }$is the slope.
$\text{ }$
$\left({x}_{0} , {y}_{0}\right) \text{ }$is the point the straight line passes through.
$\text{ }$
Here $a = - 1 \text{ " x_0=-1" } \mathmr{and} {y}_{0} = 4$
$\text{ }$
$y - 4 = - 1 \left(x - \left(- 1\right)\right)$
$\text{ }$
$\Rightarrow y - 4 = - 1 \left(x + 1\right)$
$\text{ }$
$\Rightarrow y - 4 = - x - 1$
$\text{ }$
$\Rightarrow y = - x - 1 + 4$
$\text{ }$
$\Rightarrow y = - x + 3$
$\text{ }$
$\text{ }$
Hence ,$\text{ } y = - x + 3$