X-3y=15 and y=-3x+4 determine whether the lines are parallel, perpendicular, or neither

Answer 1

Formula : Slope of the equation ax + by = c is "-a/b"

The Equations are 

x - 3y  =  15 --------------> (1)

y  =  - 3x + 4 ========>  3x + y  =  4 -----------> (2)

Slope of the Eq (1) 

m1  =  (-1)/(-3)

m1  =  1/3

Slope of the Equation (2)

m2 = -3/1

m2  =  -3

Multiply both the slopes

m1 X m2  =  (1/3) X (-3)

m1 X m2  =  - 1

Hence, The two lines are perpendicular to each other.

Answer :

The two lines are perpendicular to each other.