The slope m of a non vertical line through any two points is given by,
\
(Substitute
for m, 5 for x1, r for y1, 2 for x2 and -3 for y2)
(Subtract:
)
(Find the cross products: If
then
)
(Distributive property: a (b + c) = ab + ac)
(Multiply:
)
(Add 9 to each side)
(Commutative property: a + b = b + a)
(Additive inverse property:
)
(Additive identityproperty:
)
(Subtract:
)
(Multiply each side by negative sign)
(Product of two same signs is positive)
(Divide each side by 3)
(Cancel common terms)
\
The value of .