178k views
1 vote
Write the equation of the line in point-slope form that passes through (5, -1) and has a slope of 2/3

1 Answer

6 votes
Answer: " y = (2/3)x − (13/3) " .
________________________________________________
Note: "point-slope" form; or "slope-intercept form" is:

"y = mx + b" ;

in which "y" is on the left-hand side of the equation, with NO coefficient (except for the "implied coefficient of "1");

m = the slope; and is the coefficient of "x" ;

b = the y-intercept; or the value of "x" at the point which "y = 0" .
____________________________________________________
We are given the following point on the line: (5, -1).

We are given the slope, " m = 2/3 " .

Note the formula:

y − y₁ = m(x − x₁) ; Given "x₁ = 5" ; "y₁ = -1" ; "m = 2/3" ;

Plug in these known values into the formula:
_______________________________________________
y − (-1) = (2/3)*(x − 5) ;

to get:
_______________________________________________
y + 1 = (2/3)x − (2/3)*(5) ;
_______________________________________________
Note: 5* (2/3) = 5/1 * 2/3 = (5*2)/(1*3) = 10/3
_______________________________________________
y + 1 = (2/3)x − 10/3 ;
_______________________________________________
Subtract "1" from EACH side of the equation:
_______________________________________________
y + 1 − 1 = (2/3)x − (10/3) − (1) ; {Note: "3/3 = 1"}.

Rewrite as:
_______________________________________________
y + 1 − 1 = (2/3)x − (10/3) − (3/3) ;

to get:
_______________________________________________
y = (2/3)x − (13/3) .
_______________________________________________
User Marc Witteveen
by
8.0k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories