Question

30. Write an equation of a line passing through the points (45,18) and (49, -14)​

Answer 1

y = - 8x + 378

Explanation:

the equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

calculate the slope m, using the slope formula

m =
`(y_(2)-y_(1) )/(x_(2)-x_(1) )`

let (x₁, y₁ ) = (45, 18 ) and (x₂, y₂ ) = (49, - 14 )

substitute these values into the formula for m

m =
`(-14-18)/(49-45)` =
`(-32)/(4)` = - 8 , then

y = - 8x + c ← is the partial equation

to find c, substitute either of the 2 points into the partial equation

using ( 45, 18 ) for x and y in the partial equation

18 = - 8(45) + c = - 360 + c ( add 360 to both sides )

378 = c

y = - 8x + 378 ← equation of line