The answer is: "
y = − x − 4 " .
_________________________________________________________Explanation:_________________________________________________________Given a linear equation in "slope-intercept form" ; that is:
"
y = mx + b " ;
________________________________________________A line that is PARALLEL to the aforementioned equation has the same slope (i.e the same value for "m" ) ; and the given the [x and y coordinates of any particular point] on the parallel line; " (x₁ , y₁)" ; we can write the equation of the parallel line—in "slope-intercept format" — by using the following equation/formula:
y − y₁ = m(x − x₁<span>) ;
</span>
in which: "m = the slope"
and plug in the values for: "m" ; and "x₁" and "y₁" ;
We are given the coordinates of a particular point on the line that is parallel:
" (-4, 1) " ;
as such: x₁ = -4 ; y₁ = 1 ;
& we are given: "m = −
" .
_____________________________________________So:
→ y − y₁ = m(x − x₁) ;
→ y − 1 = −
[x − (-4) ] ;
→ y − 1 = −
(x + 4) ;
→ y − 1 = −
(x + 4) ;
Now; let us examine the "right-hand side of the equation" ;
We have: −
(x + 4) ;
__________________________________________________Note the "distributive property" of multiplication:__________________________________________a(b + c) = ab + ac ;a(b – c) = ab – ac .__________________________________________As such:
__________________________________________ −
* x + (−
* 4) ;
= −
* x + (−
*
) ;
Note: Examine the
" (−
*
) " ;
→ EACH of the 2 (TWO) "4's" cancel out to "1"s" ;
{ since: "4 ÷ 4 = 1" } ;
and we can rewrite the: "(−
*
) " ;
as: " (−
*
) " ;
Note that: "{-5 ÷ 1 = -5} ; and: "{1 ÷ 1 = 1} ;
so, rewrite the: "" (−
*
) " ;
as: "{-5 * 1}" → which equals: = " -5" ;
So:
−
* x + (−
*
) ;
= -
x + (-5) ;
= -
x − 5 ;
______________________________________________→ Now, bring down the "y −1" ; which goes on the left hand side;
→ y − 1 = -
x − 5 ;
Add "1" to EACH SIDE of the equation; to isolate "y" as a single variable on the "left-hand side" of the equation ; & to write the equation of the particular parallel line in "slope-intercept format" ;
→ y − 1 + 1 = -
x − 5 + 1 ;
_______________________________________________________to get:
_______________________________________________________→ "
y = − x − 4 " .
_______________________________________________________