Answer:
r = 13
Step-by-step explanation:
The first step is to find b from y=mx=b using m=4/3 and (-4,8)
After solving the equation, b will equal -16/3 making the final equation be
Using the equation, you can solve for r.
This will bring the answer being r = 13
The answer is -1 , because when you add a negative number to a positive number the negative number will subtract , and vise versa.
The correct answer is: [D]: " y = - 4x − 13 " .
______________________________________________
Explanation:
_____________________________________________________
All the answer choices given are written in "point-slope format" (also known as "slope-intercept format" — that is: " y = mx + b" .
All of the answer choices given have a slope of "-4" ; that is: "m = -4" .
_____________________________________________________
The only answer choice with the equation that passes through point
"(-3, 1)" — that is, when "x = -3, y = 1" — is:
___________________________________________________
Answer choice: [D]: " y = - 4x − 13 " .
___________________________________________________
In the equation: " y = - 4x − 13 " ; when "x = - 3, y = 1" .
____________________________________________________
Given: " y = - 4x − 13 " ;
↔ - 4x − 13 = y ;
Plug in "(-3)" for "x" ; and see that "y = 1" ;
-4(-3) − 13 = y ;
12 − 13 = y = -1 ;
______________________________
So, when x = -3, y = 1 .
_________________________________________
The correct answer is: [D]: " y = - 4x − 13 " .
___________________________________________
Consider choice: [A]: " y = - 4x + 13 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) + 13 = y ; 12 + 13 = 25 ; NOT "-3" .
______________________________________
Consider choice: [B]: " y = - 4x + 7 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) + 7 = y ; 12 + 7 = 19 ; NOT "-3" .
______________________________________
Consider choice: [C]: " y = - 4x − 7 " ;
Substitute "(-3)" for "x" and see if "y = -1" ;
-4(-3) − 7 = y ; 12 − 7 = 9 ; NOT "-3" .
___________________________________________
This leaves us with "Answer choice: [D]: " y = - 4x − 13 " ; the only remaining answer choice; which we have already confirmed is correct; so we do not need to check.
_______________________________________________
Hope this helps!
______________________________________________
